Glossary of Computer Related Terms
A
access
The reading or writing of data; as a verb, to gain entry to
data. Most commonly used in connection with information access, via a user ID,
and qualified by an indication as to the kinds of access that are permitted.
For example, read-only access means that the contents of the file may be read
but not altered or erased.
Access Control List
(ACL) A list of the services available on a server, each
with a list of the hosts permitted to use the service.
access time
The time interval between the instant that data is requested
and the instant that it is received.
account
Your subscription to a networked computer system.
account name
Same as your login ID or user ID. The word you type at the
"Login:" prompt; your electronic name.
address
A character or group of characters that identify a register,
a location or some other data source or destination.
aggregate
n. A total created from smaller units. For instance, the
population of a county is an aggregate of the populations of the cities, rural
areas, etc. that comprise the county.
v. To total data from smaller units into a large unit. Example: "The Census Bureau aggregates data to preserve the confidentiality of individuals."
v. To total data from smaller units into a large unit. Example: "The Census Bureau aggregates data to preserve the confidentiality of individuals."
aggregate data
Data that have been aggregated.
algorithm
A set of rules for solving a problem in a given number of
steps.
alias
See nickname.
analog
A method of storing information, used by most audiotapes,
videotapes and laserdiscs (and all LP phonograph records, remember those?). An
analog device uses a physical quantity, such as length or voltage, to represent
the value of a number. By contrast, digital storage relies on a coding system
of numeric units.
Application Layer
Layer seven of the OSI reference model. It serves as a means
by which applications access communications services.
application
The use to which a data processing system is put within a
given discipline, such as a payroll application, an airline reservation
application or a network application.
application program
A program that is written for or by a user that applies to
the users discipline.
application software
A group of programs designed to perform tasks that can be
tailored to a users specific needs.
archive
v. To copy programs and data onto an auxiliary storage
medium (disk, tape,etc.) for long-term retention, such as when disk space has
become full.
n. A file with a structure that allows storage of multiple files within it in such a way that the names of the files can be listed and files can be individually added and deleted. The terminology is typically associated with microcomputers. On a mainframe, such a file is typically called a library.
n. A file with a structure that allows storage of multiple files within it in such a way that the names of the files can be listed and files can be individually added and deleted. The terminology is typically associated with microcomputers. On a mainframe, such a file is typically called a library.
argument
A value supplied to a procedure, macro, subroutine, or
command that is required in order to evaluate that procedure, macro,
subroutine, or command. Synonymous with parameter.
ASCII
American Standard Code for Information Interchange
(pronounced ask-ee). The form in which text characters are handled in most
computer systems and networks. ASCII text has no special characters for formatting
such as underlined or bold characters, font changes, etc., thus can be viewed
on any personal computer or terminal.
assembler
A program that converts symbolically-coded programs into
object level, machine code. In an assembler program, unlike a compiler, there
is a one-to-one correspondence between human-readable instructions and the
machine-language code.
ATM
Asynchronous Transfer Mode. A standard for cell relay that
uses fixed length cells of 53 bytes, 5 bytes of which are headers. Can support multiple
services including voice, video and data.
ATM Forum
An industry-wide effort that is now an international
consortium of more than 400 companies who define ATM interoperability
specifications and promote industry-wide cooperation to help proliferate ATM
and thus drive implementation costs down.
audit
A personal or computerized review process that accounts for
the adequacy, effectiveness, security and overall functionality of a data
activity.
authentication
Process of establishing who you are.
authorization
Permission to access non-public information or use equipment
that is either fully or partially restricted. Process of establishing what you
can do.
autonomous system
A collection of one or more networks that are administrated
by the same entity. Each regional network (such as SURAnet) is an autonomous
system.
B
backbone
Refers to a piece of cable used to connect different floors
or departments together into a network. Also generalized to a network that
connects networks together.
background processing
Users may use a terminal for one project and concurrently
submit a job that is placed in a background queue that the computer will run as
resources become available. Also refers to any processing in which a job runs
without being connected to a terminal.
backspace
A keyboard operation that moves the cursor one place to the
left. A destructive backspace erases characters as it goes, thus allowing users
to modify what has been typed (distinguished from the left- arrow key).
backup
n. A resource that is or can be used as a substitute when a
primary resource fails or when a file has been corrupted.
v. To save as in to make a copy in case of future failure or corruption.
v. To save as in to make a copy in case of future failure or corruption.
bandwidth
A piece of the spectrum occupied by some form of signal,
where it is television, voice, fax data, etc.. Signals require a certain size
and location of bandwidth in order to be transmitted. The higher the bandwidth,
the faster the signal transmission, and thus allowing for a more complex signal
such as audio or video. Because bandwidth is a limited space, when one user is
occupying it, others must wait their turn. Bombarding the Internet with
unnecessary information is referred to as "taking up bandwidth."
baseband
A network medium that uses only one carrier frequency.
Examples are Ethernet and PhoneNet.
BASIC
Beginners All-purpose Symbolic Instruction Code. A commonly
used personal-computer language, first developed at Dartmouth during the 1960s.
batch processing
Originally, a method of organizing work for a computer
system, designed to reduce overhead by grouping similar jobs. In one scheme,
jobs were collected into batches, each requiring a particular compiler. The
compiler was loaded, and the jobs submitted in sequence to the compiler. The
term has come to be applied to background processing of jobs not requiring user
intervention on multiuser systems. See compiler.
batch query
A query that has been saved so that it can be used more than
once and run in the background.
binary
A file containing one or more strings of data bits which are
not printable characters. Some binary files may be computer programs or other
forms of data that contain no text characters at all. Binary files cannot be
displayed on screen, but can be downloaded for use with appropriate
applications on your computer. Binary (base 2) is also the building block of
computer information, representing "on" or "off" and
"true" or "not true" as 1 or 0.
binary number
A number written using binary notation which only uses zeros
and ones. Example: decimal number seven in binary notation is: 111.
bit
A binary digit, either a 0 or 1. In the U. S. , 8 bits make
up one byte; in Europe, byte equals one word.
bitmapped terminal
A terminal that can turn individual screen dots on or off.
BITNET
Because Its Time NETwork. Started in 1981 by City College of
New York and Yale University, it is a network linking hosts at educational and
research institutions in the United States, Canada, Europe and other countries
using the RSCS protocols. Merged with CSNet to form CREN.
bits per second (bps)
The speed at which bits are transmitted.
block
A sequence of words or characters written contiguously, such
as into a group, by a computer and stored on a disk, diskette, magnetic tape,
etc.
bold
A way of emphasizing a word of text, as in darker type or
brighter characters on a video display terminal.
booting
Turning on your computer.
break
An interruption to a transmission; usually a provision to
allow a controlled terminal to interrupt the controlling computer.
bridge
A device that connects two networks and passes traffic
between them based only on the node address, so that traffic between nodes on
one network does not appear on the other network. For example, an Ethernet
bridge only looks at the Ethernet address.
broadband
A communications medium on which multiple signals are
simultaneously transmitted at different frequencies. Also refers to switching
capability implemented on this medium that allows communication between devices
connected to it. In telecommunications it is defined as any channel with a
bandwidth greater than voice grade (4 KHz).
broadcast
A single message addressed to all nodes on a network.
browser
A software tool used to read electronic documents. Mosaic,
NetScape and Lynx are the most popular browsers.
buffer
A temporary memory for data, normally used to accommodate
the difference in the rate at which two devices can handle data during a
transfer.
bug
An error. Can be a hardware malfunction or a software
programming error.
bulletin board (BBS)
A computer system which can be called using a modem.
BUS topology
Network wiring commonly used by Ethernet in which all nodes
on the network see all packets.
byte
A group of adjacent binary digits, usually 8, on which a
computer operates as a unit; often used to represent a single character. (See
bit. )
C
cable
A set of wires connecting pieces of computer hardware.
carriage return
The or key on your keyboard. On-line commands often must be
followed by .
CD-ROM
Compact Disk - Read Only Memory. Optical (CD) disks that are
mastered and then can only be read; i.e., the data cannot be manipulated,
removed, etc.
cell relay
Packet-switching using small, fixed-sized packets called
cells. The fixed size allows for very high speed switching. It is the basis for
SMDS and ATM.
channel
Any medium by which information can be transmitted. For
example, the air is a channel for our voices just as much as a fiber optic line
can be data for a video signal.
character
Any symbol (usually alphabetic, numeric, or punctuation)
that can be entered into your computer.
character set
A set of characters handled by a specified machine; sets
include alphabetic characters, numbers, symbols, graphics characters, a space
character and control characters. Graphics characters denote a printed mark;
control characters produce some particular effect. Two of the most widely used
sets are ASCII and EBCDIC.
chip
A tiny piece of semi-conductive material, usually based on
silicon, used in the manufacture of electronic components.
client
A computer program that uses the services of another
computer program. Software that extracts information from a server; your
auto-dial phone is a client, and the phone company is its server.
client/server
A relationship in which client software obtains services
from a server on behalf of a person.
Client-Server Interface
An architecture that provides for the splitting of user
requests (usually called clients) and a related server function, most commonly
across a network. The combined effect is to provide the clients with access to
some service such as databases, printing, etc.
COBOL
COmmon Business Oriented Language The first standardized
computer language. At Emory it is most commonly used for administrative
applications.
code
n. A language for expressing operations to be performed by a
computer.
v. To write in such a language.
v. To write in such a language.
collision
The result of two nodes transmitting at the same time on a
multiple access network such as Ethernet. Both packets may be lost or partial packets
may result.
column
A vertical arrangement of characters or other expressions.
command
A request, typed from a terminal or embedded in a file, to
perform an operation or to execute a particular program.
communications line
A physical medium (wire, microwave beam) used to transmit
data.
communications program
A program that makes a computer act as a terminal to another
computer. Communications programs usually provide for file transfer between
microcomputers and mainframes.
compiler
A program that translates human-readable programs into a
form the computer understands. The input (source code) to the compiler is a
description of an algorithm in a problem- oriented language; its output (object
code) is an equivalent description of the algorithm in a machine-oriented
language.
computer
A device or system that is capable of carrying out a
sequence of operations in a distinctly and explicitly defined manner. The
operations are frequently numeric computations or data manipulations, but also
include data input and output. The ability to branch within sequences is its
key feature.
concentrator
A device that brings together at a common center connections
to a particular kind of network (such as Ethernet), and implements that network
internally.
conference
An electronic meeting place dedicated to a particular
subject where users come to participate in discussions or group projects.
Conferences can be used to post a variety of information such as news services,
newsletters, and statistics; also called "newsgroups," "bulletin
boards," or "echoes." An electronic conference provides a
many-to-many communication medium, as opposed to the person-to-person nature of
e-mail. All conferences have a particular subject or purpose, and the topics
and responses they contain might provide items of news, ideas, questions, or
other information in almost any form. Some special-purpose conferences may have
restricted access, allowing some users to write messages, some only to read,
and some neither. The person responsible for the technical maintenance and/or
community communication is called the "conference facilitator."
configuration
The particular hardware elements and their interaction in a
computer system for a particular period of operation.
connect time
Time that elapses while the user of a terminal is connected
to a time-sharing system; it is measured by the duration between logon and
logoff.
control character
One of 32 characters of the ASCII character set that defines
a control function for a character entry and display device such as a terminal.
Examples are carriage return, tab, form feed and bell.
control key
A special function key on a computer keyboard, frequently
used in combination with alphabetic keys, to enter commands.
copy
A function that reads data from a source, leaving the source
data unchanged and writes it elsewhere. One example would be to copy a deck of
punched cards onto magnetic tape.
CPU
Central Processing Unit. The main internal component of a
computer where executions of instructions are carried out and calculations are
performed.
crash
A computer system is said to crash when it stops working for
some reason and must be restarted.
cursor
A symbol on a display screen that indicates the position at
which the next character entered will be displayed. The symbol often blinks so
that it can be easily noticed.
cursor control
The keyboard keys used to position the cursor on a display
screen. They are usually keys labeled with arrows indicating the direction of
movement.
Cyberspace
The nebulous "place" where humans interact over
computer networks (the Internet is considered Cyberspace). Coined by William
Gibson in Neuromancer.
D
Data Link Layer
Layer two of the OSI reference model. It controls the
transfer of information between nodes over the Physical Layer.
data
Information suitable for communication, interpretation or
processing by a computer.
data communications
The collection and redistribution of data through
communications channels, often including operations such as coding, decoding
and validation.
data entry
The entry of data into a computer or onto a
computer-readable medium by an operator from a single data device, such as a
card reader or keyboard.
data processing
The systematic performance of operations upon data, for
example, handling, merging, sorting and computing.
Dataset
A file or group of files associated with one part of a
study.
database
A collection of interrelated data values that may be
integrated permanently into a single connected structure or integrated
temporarily for each interrogation, known as a query. In its most technical
sense, database implies that any of the data may be used as a key for specific
queries. In more common usage it means any accessible collection of information
and that only a limited set of data values may be used to specify queries.
database management system
A systematic approach to storing, updating, securing and
retrieving information stored as data items, usually in the form of records in
one or more files.
DBMS
DataBase Management System.
debug
To detect, trace and eliminate errors in computer programs.
default
A software function or operation which occurs automatically
unless the user specifies something else.
delete key
Personal computers normally allow deletion of typing
mistakes by either the backspace key or the Del key. Users must either specify
which of these keys they wish to use, or set their communication software to
match whichever key the network expects.
DHCP
Dynamic Host Configuration Protocol. Supports booting
workstations and other devices that need information from outside before they
can complete the booting process, such as an IP number or name of program file
to download.
dial-up
To connect to a computer by calling it on the telephone.
dictionary file
A special form of machine-readable codebook that contains
information about the structure of a datafile and the locations and, often, the
names of variables variables in the datafile. Typically, you use a dictionary
file and a datafile together with statistical software; the statistical
software uses the dictionary so that you may specify variables by name, rather
than having to specify their locations in the file.
digital
Used in computerese to describe information that can be
represented by a collection of bits.
direct access
The ability to read or write data directly from or to any
location on a storage device without having to refer to data that was
previously written. Files written with direct access do not have to be read
sequentially starting at the beginning.
directory
A logical container of files and other directories;
synonymous with folder. Typically implemented as a file that contains pointers
(directions) to files or other directories.
disk or diskette
A small, flat, either rigid or floppy magnetic disk for
storing data permanently. Magnetic medium for data storage. Either
"floppy" diskettes (720K to 1.4 megabytes), or "hard" disks
(usually 20 megabytes or more).
display
A device that enables information, either textual or
pictorial, to be seen but not permanently recorded. The most widely used kind
is the cathode-ray tube.
distributed
Processing resides in more than one computer in a network.
distributed application
Application designed so that components run on different -
but cooperating - systems on a network.
distributed database
The data resides in more than one physical database in a
network. Access to the data involves more than one database server. Clients may
have to connect to more than one server directly and integrate the data they
receive according to the applications needs.
distributed file system
Allows files on remote nodes of a network to appear locally
connected.
document
A medium and the data recorded on it for human use; for
example, a report sheet or book. By extension, any record that has permanence
and that can be read by human or machine.
documentation
A collection of organized documents or the information
recorded in documents. Also instructional material specifying the inputs,
operations and outputs of a computer program or system.
DOS
Disk Operating System. A Microsoft program that controls a
computers transfer of data to and from a hard or floppy disk. DOS generally
refers to the operating systems for the IBM PCs and their clones. Also the name
of an old operating system on IBM mainframes.
dot-matrix printer
A printer that creates each character from an array of dots.
The dots are formed by pins striking a ribbon against the paper, one pin for
each dot position. The printer may be a serial printer (printing one character
at a time) or a line printer.
down
A computer is down when it is not running. It may be shut
down for maintenance, hardware failure, or failure of the operating system or
user program.
download
The transfer of information from a remote computer system to
the users system. Opposite of upload.
downtime
The time interval during which equipment is nonfunctional.
drag and drop
A protocol supported by OPEN LOOK and Macintosh System 7
that allows a user to specify the input file to an application by dragging the
icon representing the file onto the applications icon and dropping it there.
OPEN LOOK also recognizes dragging the icon into the applications input panel.
For example, dragging a files icon into the printool application causes it to
be printed.
drive
A generic term used to identify the equipment that serves as
a player or recorder for a storage medium.
dump
A printed representation of the contents of a computer
storage device, usually main memory, backed-up when a system crash or other
failure has occurred. As a verb, refers to a large amount of data.
E
edit
To enter, modify or delete data.
editor
A program that permits the review and editing of the
contents of a file.
electronic mail. Information exchanged by electronic means
in a manner analogous to that provided by the postal service.
e-mail address
The way you specify where an E-Mail message should be
delivered.
e-mail server
A computer system that provides MTA, mailbox storage and
directory services and optionally UA services.
e-mail service
UA, MTA, mailbox storage, and directory service.
encapsulation
Combining or defining a data structure of attributes and a
group of associated functions and behaviors as a single object.
enter key
A special function key on a keyboard used to transmit a line
or screen of data from a display screen to a computer. Often used
interchangeably with return key.
environment
The setting in which computing takes place that is the
aggregate of the hardware, software, policies and procedures relating to their
use. The computing environment may be influenced by software, such as the
operating system (for example, a UNIX environment) or the vendor (for example,
an IBM environment).
erase
To remove data from a data medium, leaving the medium
available for recording new data.
error message
A message that reports the detection of an error.
error checking
Uploading or downloading transfer check employed to identify
errors in data transmission.
Ethernet
A local area network originally developed by Xerox for
linking personal computers. Later adapted by DEC and Intel as well and
subsequently adopted as an international standard called 802.3. It transmits
data at 10 megabits per second. All computers on a network were originally
connected to a coaxial cable up to one kilometer. Each computer monitors all
transmissions, looking for packets containing its identifier as the
destination. Only one signal may be present on the channel at a time and no
single computer controls transmissions. Several upper layer protocols, such as
DECnet and TCP/IP use Ethernet as an underlying transport mechanism. Ethernet
is to be contrasted with other data link protocols such as token ring, DDCMP or
SDLC. Uses CSMA/CD.
execute
To interpret a computer instruction and carry out the
operations specified in the instruction.
F
fiber optics
A high speed channel for transmitting data. Made of
high-purity glass sealed within an opaque tube. Much faster than conventional copper
wire such as coaxial cable.
field
Usually the smallest data element in a record; a specified
area used for a particular category of data; for example, columns used to
represent a particular item of data, such as an employees wage (fixed field).
The particular field is always used to record the same kind of information. In
free field records, each field has an identifier that is present in the record
and linked to the contents of the field.
file
A collection of any form of data that is stored beyond the
time of execution of a single job. A file may contain program instructions or
data, which may be numerical, textual or graphical information.
file format
The type of file, such as picture or text; represented as a
suffix at the end of the filename (text = TXT or .txt, etc.).
file server
A computer designated to store software, courseware,
administrative tools, and other data on a local- or wide-area network. It
"serves" this information to other computers via the network when
users enter their personal access codes.
folder
A place where a user's e-mail messages may be stored. Every
user has a folder for new messages, and on most systems may create other
folders for specific purposes.
font
A set of consistent size, shape or style of printer
characters, including alphabetic and numeric characters and other signs and
symbols.
foreground
High-priority processing, usually for realtime activities,
automatically given precedence, by means of interrupts, over lower-priority
processing.
form
The paper on which output data is printed.
form feed
The feature that automatically advances a roll of paper to
the top of the next page or the next form when the printer has finished
printing a document or form of one or more pages.
format
The defined structure of information that is recorded on
magnetic media, displayed on a visual display device or printed on a page. Used
as a verb, it means to put data into a predetermined structure or divide a
storage medium, such as a disk into sectors, so that it is ready to receive data.
FORTRAN
FOrmula TRANslation. A high level scientific programming
language.
fragment
Partial packet caused by a collision.
frame
A packet sent over a serial link.
freeware
Software that is distributed for free, with no license fee.
frequency
A measurement of the number of electromagnetic waves that
pass over a given point in a given period of time.
FAQ
Frequently Asked Questions. A collection of information on
the basics of any given subject. Often put together and archived on a server so
that people don't waste bandwidth asking simple questions.
FTP
File Transfer Protocol. A program that allows for file
transfers over the Internet.
FUD
Fear, Uncertainty and Doubt. "FUD factor"
function key
A keyboard key that gives an instruction to a computer, as
opposed to keys that produce letters, numbers, marks of punctuation, etc.
G
garbage
Unwanted or meaningless information in memory, on disk or on
a tape.
gateway
An electronic door between one computer network and another.
A device or set of devices that connects two or more networks, enabling data
transfer between them. When the networks are similar, a gateway routes packets
or messages. When the networks differ, a gateway also performs extensive
protocol conversion.
GIF
Graphic Interchange Format. Compuserves non-platform
specific format for low-resolution, compressed graphics interchange.
gopher
A client program available via the Internet that allows
users to review and retrieve information on other host systems via easy-to-use
menus.
graphic
A computer-generated picture produced on a computer screen
or paper, ranging from simple line or bar graphs to colorful and detailed
images.
Groupware
Software that serves the group and makes the group as a
whole more productive and efficient in group tasks. Example: Group Scheduling.
GUI
Graphical User Interface. Defines a format for scroll bars,
buttons, menus, etc., and how they respond to the user.
H
handshaking
A procedure performed by modems, terminals, and computers to
verify that communication has been correctly established.
hang
When a computer freezes, so that it does not respond to
keyboard commands, it is said to "hang" or to have "hung."
hard copy
A printed copy of machine output in a visually readable
form.
hard disk
A data-recording system using solid disks of magnetic
material turning at high speeds.
hardware
Physical computer equipment such as electrical, electronic,
magnetic and mechanical devices.
hardwired
Circuits that are permanently interconnected to perform a
specific function, as distinct from circuits addressed by software in a program
and, therefore, capable of performing a variety of functions, albeit more
slowly. Also used to describe a non-switched connection between devices.
header
The portion of a message, preceding the actual data,
containing source and destination address and error-checking fields.
help
Users in need of help can often issue a command such as
"?" to access on-line help and tutorial systems.
hierarchical file
A hierarchical file is one that contains information
collected on multiple units of analysis where each unit of analysis is
subordinate to another unit. For example, if the physical housing structure is
one unit, and individual persons within the structure is another unit, the
person records are subordinate (e.g. related to) the housing unit. An example
would be the Current Population Survey Annual Demographic File which has
household, family, and person units of analysis. Studies that include data for
different units of analysis often link those units to each other so that, for
instance, one can analyze the persons as they group in a structure. Such
studies are sometimes referred to as having a relational structure.
hierarchical file structure
A format for storing hierarchical files . Each unit of
analysis has its own record structure or record type . Different units of
analysis do not necessarily have the same number of bytes or characters as the
records for other units of analysis. In order to give such a file a common
physical record length , short logical records are typically "padded"
with blanks so that they will all be the same physical record length. A
hierarchical file can be also be stored in a rectangular file . For instance,
the Survey of Income and Program Participation is distributed both ways; users
can choose the format they prefer. Typically, the hierarchical file structure
is more space-efficient but more difficult to use.
host
A computer that is made available for use by multiple people
simultaneously.
host computer
In the context of networks, a computer that directly
provides service to a user. In contrast to a network server, which provides
services to a user through an intermediary host computer.
HTML
Hypertext Markup Language. A convention of codes used to
access documents over the World-Wide Web. Without HTML codes, a document would
be unreadable by a Web browser.
HTTP
HyperText Transfer Protocol. Extremely fast protocol used
for network file transfers in the WWW environment.
hub
A device that is a center of network activity because it
connects multiple networks together.
hyperlink
A pointer that when chosen displays the item to which it
points. It typically takes the form of a button or highlighted text that points
to related text, picture, video, or audio. Hyperlinks allow non-linear
exploration of media that contain them.
hypermedia
Media (such as text, graphics, video, audio) that contains
hyperlinks.
hypertext
A document which has been marked up to allow a user to
select words or pictures within the document, click on them, and connect to
further information. The basis of the World-Wide Web.
I
icons
On-screen pictures that symbolize various commands.
I/O
Input/Output. The part of a computer system or the activity
that is primarily dedicated to the passing of information into or out of a
central processing unit.
IEEE
Institute of Electronic and Electrical Engineers. A leading
standards-setting group in the United States.
inbox
The mailbox that holds incoming e-mail.
index
A list of the messages contained in a conference or a mail
folder. Indexes generally show the date of the message, its title (or subject),
the name of the user who wrote it, and an indication (with a "*"
marker) of whether you have read that message.
information hiding
A technique by which the structure and precise usage of
information and data is concealed. The information is private to its owning
objects and accessible to all other objects only by sending a message to the
owner. This is the basis of encapsulation.
information server
A computer on the Internet which acts as a library of
documents and files that users can download.
information superhighway
A term popularized by Vice President Al Gore. According to
his vision, it is a high-speed network of computers that will serve thousands
of users simultaneously, transmitting E-mail, multimedia files, voice, and
video.
inheritance
The ability of hierarchically-arranged objects to acquire
attributes and behaviors of objects above them without duplicating the code.
input
As a verb, to enter information, instructions, text, etc. ,
in a computer system or program. As a noun, the data so entered. Input devices
include the keyboard and OCR reader.
instance
A particular occurrence of an object defined by a class. All
instances of a class share the behavior implemented and inherited by the class.
Each instance has its own private set of the instance variables implemented and
inherited by the class.
instantiation
The act of creating an instance of a class.
instruction
A statement to the computer that specifies an operation to
be performed and the values and locations of the data to be processed.
interactive
Pertaining to an application in which each entry evokes a
response from a system or program, as in an inquiry system, for example, an
airline reservation system. An interactive system may also be conversational,
implying continuous dialog between the user and the system.
INTERNET
A concatenation of many individual TCP/IP campus, state,
regional, and national networks (such as CSUNET, SUPERNET, WESTNET, NSFNET,
ARPANET) into one single logical network all sharing a common addressing
scheme. The global "network of networks" that connects huge
corporations, small businesses, universities, and individuals. Every Internet
user can send E-Mail to every other Internet user. Most Internet users can also
read and post Netnews messages. In addition, many Internet users have access to
more advanced services for information search and retrieval, such as Gopher,
FTP, WWW, and WAIS.
IP
Internet Protocol. The Internet standard protocol that
provides a common layer over dissimilar networks, used to move packets among
host computers and through gateways if necessary.
IP Address
The numeric address of a computer connected to the Internet;
also called Internet address.
interrupt
A suspension of a process, such as the execution of a
computer program, caused by an event external to the computer and performed in
such a way that the process can be resumed. Events of this kind include sensors
monitoring laboratory equipment or a user pressing an interrupt key.
IRC
Internet Relay Chat, or just Chat. An on-line group
discussion.
ISDN
Integrated Services Digital Network. An international
communications standard for a common interface to digital networks that allows
the integration of voice and data on a common transport mechanism. Proposed by
Bellcore for transmission of data, voice and higher-bandwidth technologies over
phone lines.
ISO
International Standards Organization. International standard
making body responsible for the OSI network standards and the OSI reference model.
J
job
A set of data that defines a unit of work for a computer; it
usually includes all necessary computer programs, linkages, files and
instructions to the operating system.
JPEG
Joint Photographic Experts Group. The ISO proposed standard
for compression of digital data, especially 24-bit color images. It is lossy in
that it reduces the file size at the expense of image quality. PostScript Level
2 color printers are supposed to be able to receive, decompress and print JPEG
compressed images. Uses quantization and Huffman encoding.
justify
In word processing, to print a document with even (straight,
non-ragged) right and left margins.
K
Kermit
A communications protocol that allows you to transfer files
between your computer and on-line network systems. Kermit has built-in error
correction and can handle binary (non-text) files.
key
An identifier in a database or file. A primary key is a
unique identifier. A secondary key is typically not unique. A key may be used
to specify data in a query. Example: Tag number to specify a car in a database
of automobile registration information.
keyboard
Similar to a typewriter, contains the letters for typing
text, and keys that give the computer its commands.
kilobyte(K)
1,024 bytes, often used to mean 1,000 bytes.
L
LAN
Local Area Network. A network that usually covers a
contiguous and fairly small geographical area.
LAN e-mail system
An e-mail system in which the UA runs on LAN-attached workstations.
laserdisc
Large, metallic-looking records about the size of 33 RPM
albums (12 inches in diameter), sometimes called videodiscs. Laserdiscs can
store a vast amount of information in text, sound, and images. To play a
laserdisc, you need a laserdisc player and either a computer monitor or
television set. Laserdiscs come in two formats. CLV (constant linear velocity)
is accessed by time and CAV (constant angular velocity) is accessed by frame
number.
laser printer
A electrophotographic (xerographic) printer in which a laser
is used as the light source.
Layer
A grouping of related tasks involving the transfer of
information. Also, a level of the OSI reference model.
line
In communications, a wire connecting a terminal to a
computer; also a unit of text.
line editor
An editor where the text is considered to be a series of
lines separated by end-of-line markers and in which alterations are made to
individual lines or groups of lines through editor commands.
line printer
A computer output device in which an entire line of print is
composed and determined within the printer prior to printing. The line is
printed as a unit and there is no movement of a print head.
link
A form of markup which designates that data within a
document will automatically connect with either nested data or an outside
source. Used in the design of hypertext.
LISTSERV
A server that manages named lists of recipients and files
and access-controls for them. Accepts commands by interactive message or
electronic mail. A note sent to a list name is resent to each recipient in the
list. Will send a copy of a file on command.
load
v. To transfer a program held on some external storage
medium (such as magnetic tape or disk) into the main memory of the machine in a
form suitable for execution.
logical record
All the data for a given unit of analysis . It is
distinguished from a physical record because it may take several physical
records to store all the data for a given unit of analysis. For instance, in
Card Image data, a "card" is a physical record and it usually takes
several "cards" to store all the information for a single case or
unit of analysis.
login or logon
The opening sequence of keystrokes used via computer screen
instructions to connect to a system or begin operations on a computer.
login ID
Same as account name or user ID.
logoff
Leave a network system, usually by typing "bye" or
"q" for quit. Sometimes called "logout."
Longitudinal Study
In survey research, a study in which the same group of
individuals is interviewed at intervals over a period of time. See also: panel
study . Note that some cross sectional studies are done regularly (for
instance, the General Social Survey and the Current Population Survey (Annual
Demographic File) are conducted once a year), but different individuals are
surveyed each time. Such a study is not a true longitudinal study.
LPR
Line Printer Remote. A protocol that allows one system to
send a file to another system to be queued to a device to which the receiving
system has access.
lynx
A text-based World-Wide Web browser. Because it does not
employ a graphics capability, it allows slower computers (or computers using a
modem) to access the Internet with ease.
M
machine language
A programming language or instruction code that is
immediately interpretable by the hardware of the machine concerned.
macro
A single computer instruction that stands for a given
sequence of instructions.
magnetic disk
A flat circular plate with a magnetizable surface layer used
for storage of data.
magnetic tape
A tape with a magnetizable surface layer on which data can
be stored by magnetic recording.
A RiceMail UA that can send mail and operate on incoming
messages.
mailbox
A file of e-mail messages on which a UA can operate as if
they were incoming messages (read, reply, forward, delete, etc). Compare with
inbox.
MAILER
A BITNET MTA for VM/CMS that natively supports domain names
and routing through gateways. It is supplied without charge to BITNET members
by Princeton University.
main memory
Usually the fastest storage device of a computer and the one
from which instructions are executed.
mainframe
The cabinet that houses the central processing unit and main
memory of a computer system, separate from peripheral devices such as card
readers, printers, disk drives, etc. and device controllers. The term has come
to be applied to the computer itself in the case of large systems. A large
computer system; the IBM ES9000.
mainframe, minicomputer, micro-computer
Three sizes of computers. Big corporations use mainframes
and large school systems might use a mid-range computer, sometimes called a
minicomputer, as a file server and administrative tool. The correct term for
microcomputer is personal computer or PC.
MB
Megabytes. 1,048,576 bytes, often used to mean one million
bytes (1,000,000) bytes.
medium
The material used to support the transmission of data. This
can be copper wire, coaxial cable, optical fiber, or electromagnetic wave as in
microwave.
memory
A device or medium that serves for temporary storage of
programs and data during program execution. The term is synonymous with
storage, although it is most frequently used for referring to the internal
storage of a computer that can be directly addressed by operating instructions.
Your computer's temporary storage capacity, measured in kilobytes (KB) or
megabytes (MB) of RAM (random-access memory). Long-term data storage on discs,
is also measured in kilobytes or megabytes.
menu
A displayed list of options from which a choice can be made.
The list is often displayed with a code opposite each option; the selection may
be made by typing the appropriate code.
message
E-Mail: The unit of information transferred by an e-mail
system. It consists of an envelope that identifies the recipients to an MTA;
headers containing who the message is from, to, subject, relaying information,
etc; and a body that contains the information the sender wishes to communicate.
method
A procedure whose code implements the behavior invoked by
sending a message.
methodology
A methodology is a collection of methods and tools, designed
and arranged so as to provide guidance in achieving a specific objective.
microcomputer
A computer system in which the central processing unit is
built as a single tiny semiconductor chip or as a small number of chips.
microprocessor
Main computer chip that provides speed and capabilities of
the computer. Also called CPU.
Microwave
Bandwidth ranging above one gigahertz, used for high-speed
data transmission.
mission
Purpose; what you are in business to do.
modem
Short for MOdulation/DEModulation, it is a device that can
convert a digital bit stream into an analog signal (modulation) and can convert
incoming analog signals back into digital signals (demodulation). The analog
communications channel is typically a telephone line and the analog signals are
typically sounds.
modem setup
Modem speed or baud rate, parity, data bits, stop bits, and
duplex must be set the same at the user's computer as at the network system.
Communication software is used to set up the modem.
module
A logically self-contained and discrete part of a larger
computer program.
monitor
A television-like screen that shows text, graphics, and
other functions performed by the computer.
Mosaic
An Internet-based, global hypermedia browser that provides a
unified interface to the various protocols, data formats, and information
archives (i.e. gopher) used on the Internet and enables powerful new ways for
discovering, using, viewing, and sharing information. It was developed by NCSA
as part of the WWW project.
mouse
A device that is moved by hand to move a pointer to indicate
a precise position on a display screen. The device has one or more buttons on
top and a cable connected to a computer; it may use wheels and be
friction-driven or it may use light reflected from a special pad.
multimedia
A single work assembled using elements from more than one
medium, such as high-resolution color images, sounds, video, and text that
contains characters in multiple fonts and styles.
multimedia mail
Provides the capability to compose, send and read messages
that include things such as spreadsheets, line drawings, animated graphics,
high-resolution color images, digitized speech, video, and WYSIWYG text that
may contain characters in multiple fonts and styles, etc.
multiplexer
A device that merges information from multiple input
channels to a single output channel.
multiuser
The capability of some computer systems to provide access to
many simultaneous users.
N
nesting
Placing documents within other documents. Nesting allows a
user to access material in a non-linear fashion - this is the primary factor
needed for developing hypertext.
NetScape
One of the most recent developments in browsing technology,
it is considered to be faster than the original Mosaic. Oddly enough, it has
been designed by the Mosaic Corporation, made up of programmers that authored
Mosaic in the first place.
Network Layer
The third layer of the OSI reference model. It controls
underlying telecommunications functions such as routing, relaying, and data
link connections.
network
A collection of two or more computers interconnected by
telephone lines, coaxial cables, satellite links, radio, and/or some other
communication technique. A computer "network" is a group of computers
which are connected together and which communicate with one another for a
common purpose. Computer networks support "people and organization"
networks, users who also share a common purpose for communicating.
nickname
A name that can be used in place of an e-mail address. Same
as alias.
node
A member of a network or a point where one or more
functional units interconnect transmission lines. A VAX is a node on a DECnet.
noise
Undesirable signals bearing no desired information and
frequently capable of introducing errors into the communication process.
O
object
An entity consisting of attributes (such as color and size)
stored as data and behaviors or functions (such as draw and move) that
manipulate the attribute data. It is capable of interacting with other objects.
As defined by OMG: encapsulation of the attributes, relationships, and methods
of software-identifiable program components. Complete and reusable pieces of
data or applications. Essentially packets of program code wrapped with data
that behave like things in the real world.
object-based
Supports the concept of the object and the use of messages
to communicate between the objects.
object code
Output from a compiler or assembler that is itself
executable machine code or is suitable for processing to produce executable
machine code.
object-oriented
Supports the concepts of objects, encapsulation, message
passing, dynamic binding and inheritance.
object-oriented technology
A collection of languages, tools, environments and
methodologies aimed at supporting development of software applications centered
around interrelated, interacting objects.
OLE
Object Linking and Embedding. A Microsoft approach that
allows data from one OLE application to be placed in any document of another
OLE application in such a way that you can edit the object using the first
application's capabilities without leaving the second application. With OLE2.0
you can move data using drag and drop within and between documents and
applications. OLE automation provides a cross-platform infrastructure that
allows one application to control another.
off-line
Not connected to a network. You can save money on
pay-for-use networks by preparing your messages off-line using your
word-processing software, and uploading them instead of typing them in while
you're connected to (or on-line with) the network.
on-line
Active and prepared for operation. Also suggests access to a
computer network. Connected to a network or via a network. Examples: Send me a
message on-line. In other words, send me an e-mail message.
Online Service
Commercial online services like America Online, CompuServe,
and Prodigy enable their users to send and receive Internet E-Mail, although
they don't yet offer access to most other Internet services.
open
Under open systems, unencumbered specifications are freely
available, independent branding and certification processes exist, multiple
implementations of a single product may be created and competition is enhanced.
open platform
A national Internetnetwork that would allow citizens the
ability to access, create, and publish information.
open system
A system that implements sufficiently open specifications
for interfaces, services and supporting formats to enable properly-engineered
applications software to be ported with minimal changes across a wide range of
systems, to interoperate with other applications on local and remote systems,
and to interact with users in a style that facilitates user portability.
OSI
Open Systems Interconnect. An international standard suite
of protocols defined by International Standards Organization, that implements
the OSI reference model for network communications between computers.
OpenWindows
A windowing environment from Sun Microsystems based on
X-windows and NeWS.
operating system
software that controls the basic, low-level hardware
operations, and file management. It is provides the link between the user and
the hardware. Popular operating systems include: DOS, MacOS, VMS, VM, MVS,
UNIX, and OS/2. (Note that "Windows 3.x" is not an operating system
as such, since in must have DOS to work. )
output
Information retrieved from a computer, displayed by a
computer or produced by a program running on a computer.
P
packet
Basic component of communication over a network. A group of
bits of fixed maximum size and well-defined format that is switched and
transmitted as a complete whole through a network. It contains source and
destination address, data and control information. See also frame.
parameter
A variable, or quantity that can assume any of a given set
of values, of which there are two kinds: formal and actual. (See argument.)
parity
Data has even or odd parity if the number of 1 bits is even
or odd. A parity bit is a bit added to data to make the parity always even or
odd. A parity bit may be used for detection of errors in RAM as well as in data
transmitted through noisy communications channels. A parity error is detected
when data that is supposed to be even parity is not, or vice versa.
password
A string of characters that a program, computer operator, or
user must supply to meet security requirements before gaining access.
peripheral
Anything extra or added on for your computer, such as a
modem, a mouse, or a fax adapter. Peripherals can be added on externally or
installed inside the machine.
PC
Personal Computer. An IBM or IBM clone personal computer
(Microcomputer) that is used by one person, as opposed to a Macintosh.
Physical Layer
The first layer of the OSI reference model. It governs
hardware connections and byte-stream encoding for transmission.
ping
Packet Internet Groper. Probably originally contrived to
match the submariners term for a sonar pulse.
n. Slang term for a small network message (ICMP ECHO) sent by a computer to check for the presence and aliveness of another.
v. To verify the presence of. To get the attention of.
n. Slang term for a small network message (ICMP ECHO) sent by a computer to check for the presence and aliveness of another.
v. To verify the presence of. To get the attention of.
pixel
Picture Element. In computer graphics, the smallest element
of a display space that can be independently assigned color or intensity.
platform
Hardware environment that supports the running of a computer
system.
plotter
An output device for translating information from a computer
into pictorial or graphical form on paper or a similar medium.
polymorphism
A technique for generalizing a single behavior across many
kinds of objects. It simplifies software design, since a programmer need only
specify an action or behavior (such as draw) and elaborate on how it is
implemented (for example, line or ellipse).
port
That portion of a computer through which a peripheral device
may communicate. Often identified with the various plug-in jacks on the back of
your computer. On a network hub, it is the connector that receives the wire
link from a node.
portable
In computer usage, a file or program is "portable"
if it can be used by a variety of software on a variety of hardware platforms.
Numeric data files written as plain character format files are fairly portable.
post
The act of placing a message in an on-line conference. The
noun "posting" is sometimes used to refer to a conference message.
PostScript
A language defined by Adobe Systems, Inc. for describing how
to create an image on a page. The description is independent of the resolution
of the device that will actually create the image. It includes a technology for
defining the shape of a font and creating a raster image at many different
resolutions and sizes.
Power PC
A RISC CPU chip designed by IBM and Apple and manufactured
by Motorola. It features a 32/64 bit implementation and full binary
compatibility with the IBM RS/6000. Four models are planned: 601, 603, 604,and
620. The 601 borrows its basic architecture from the Model 200 RS/6000. It
adopts the internal bus structure of the Motorola 88100 and the construction
plans from the 0.5 micron chip fabrication techniques used by the Model 970
RS/6000. The 603 is an entry-level device targeted toward embedded applications
and low power consumption uses such as notebooks and low-end workstations. The
604 is a second-generation version of the 601.
Presentation layer
The sixth layer of the OSI reference model. It lets an
application interpret the data being transferred.
printer
An output device that converts the coded information from
the processor into a readable form on paper.
printout
The printed output of a computer.
procedure
A portion of a high-level language program that performs a
specific task.
process
A systematic sequence of operations to produce a specified
result; a unique, finite course of events defined by its purpose or by its
effect and achieved under given conditions. As a verb, to perform operations on
data in a process. Also an address space and the code executing in it.
program
A set of actions or instructions that a machine is capable
of interpreting and executing. Used as a verb, to design, write and test such
instructions.
programmer
A person who designs, write and tests computer programs.
programming
A notation for the precise description of computer programs
or algorithms. Programming language languages are artificial languages in which
the syntax and semantics are strictly defined.
prompt
A character or message provided by an operating system or
program to indicate that it is ready to accept input.
protocol
An agreement that governs the procedures used to exchange
information between cooperating entities and usually includes how much
information is to be sent, how often it is sent, how to recover from
transmission errors and who is to receive the information.
public domain
Not protected by copyright; you may freely make copies and
distribute them; you may make derivative works.
Q
quality
It is meeting your own specifications and meeting your
customers expectations. It is also concerned with doing the right things and
doing things right.
query
A request that specifies the manner in which data is to be
extracted from one or more databases.
queue
A sequence of stored computer data or programs awaiting
processing that are processed in the order first-in first-out (FIFO).
quit
Ends the work without writing out a new file or new version
of the exiting work file unless there is a save that interrupts before dumping
the session.
R
RAID
Redundant Array of Inexpensive Disks. A way of creating a
fault-tolerant storage system. There are 6 levels. Level 0 uses byte-level
striping. Level 1 uses mirroring. Level 2 uses bit-level striping. Level 3
stores error correcting information (such as parity) on a separate disk, and
uses data striping on the remaining drives. Level 4 is level 3 with block level
striping. Level 5 uses block level and parity data striping.
RAM
Random Access Memory. Memory in which each element can be
individually addressed and accessed with the same speed as any other element of
the memory. The main memory of a computer is usually RAM. One of the earliest
forms of RAM was called core, because it consisted of directly addressed
doughnuts or cores of ferromagnetic material each of which represented one bit.
A faster more recent form of RAM is called Dynamic RAM.
random access
Differs from direct access by the fact that each element can
be accessed with the same ease and speed as any other.
Re-engineering
The circular process of going from code to models then back
to code that might be in a different language, use a different DBMS or be more
structured.
read
To sense and retrieve or interpret data from a form of
storage or input medium.
read/write
A magnetic mechanism that can read, write and erase data
encoded as polarized patterns on magnetic disk or tape.
realtime
The processing of transactions as they occur rather than
batching them. Pertaining to an application in which response to input is fast
enough to affect subsequent inputs and guide the process and in which records
are updated immediately. The lag from input time to output time must be
sufficiently small for acceptable timeliness. Timeliness is a function of the
total system: missile guidance requires output within a few milliseconds of
input, scheduling of steamships requires response time in days. Realtime
systems are those with response time of milliseconds, interactive system in
seconds and batch system in hours or days.
record
A collection of related data or words, treated as a unit.
For example, in stock control, each invoice could constitute one record.
record length
Depending on the context, the length in bytes (i.e.,
columns) of a physical record or a logical record . On ICPSR Tape Information
Forms and on CDNet, the abbreviation "RecLen" is used for physical
record length.
record type
A record that has a consistent logical structure. In files
that include different units of analysis, for instance, different record types
are needed to hold the different variables. For example, one record type might
have a variable for income in one column and another record type might have a
variable for household size in that same column. The codebook will describe
these different structures and how to determine which is which so that you can
tell your statistical software how to interpret that particular column as
income or household size.
recovery
The process by which data bases are rebuilt after a system
fails.
rectangular file
A physical file structure. A rectangular file is one which
contains the same number of card-images or the same physical record length for
each respondent or unit of analysis . A Hierarchical file can be stored in a
rectangular file structure by storing all units of analysis in a single
physical record . For instance, each record might contain one household unit,
two family units, and four person units for each family unit. This method of
storage of hierarchical files can be very inefficient in terms of storage
space, but can make the file easier to describe and work with.
reel tape
One-half inch magnetic tape stored on round reels. Also
called Round Tape.
relational database
An organization of data into tables with each column
containing the values of a data element and each row representing a record.
relational structure
A study that includes different units of analysis,
particularly when those units are not arranged in a strict hierarchy as they
are in a hierarchical file, has a relational structure. Note that the data
could be arranged in several different physical structures to handle such a
data structure. For instance, each unit of analysis might be stored in a
separate rectangular file with identification numbers linking each case to the
other units; or, the different units of analysis might be stored in one large
file with a hierarchical file structure; or the different units could be stored
in a special database structure used by a relational data base management
system such as INGRES. An example of a study with a relational structure is the
Survey of Income and Program Participation which has eight or more record
types; these record types are related to each other but are not all members of
a hierarchy of membership. For instance, there are record types for household,
family, person, wage and salary job, and general income amounts.
remote
Equipment or site that is located out of the way or at a
distance from primary equipment or a larger or primary site. Sometimes used as
the opposite of local.
remote access
The ability to access a computer from outside a building in
which it is housed. Remote access requires communications hardware, software,
and actual physical links, although this can be as simple as common carrier
(telephone) lines or as complex as TELNET login to another computer across the
Internet.
resource
An on-line information set or an on-line interactive option.
An on-line library catalog or the local school lunch menu are examples of
information sets. On-line menus or graphical user interfaces, Internet e-mail,
on-line conferences, telnet, FTP, and Gopher are examples of interactive
options.
response
A message placed in a conference as a follow-up to a topic
or to another response; or, a reply to an e-mail message.
retiming
A function of a repeater or Ethernet hub that receives a
signal, cleans and regenerates it, and then sends it.
return key
The key on a terminal keyboard that, when struck, places the
cursor at the left margin one line below its previous horizontal position.
reuse and reuseability
An approach to software engineering that emphasizes reusing
software assets, including designs and code, and building software assets
likely to be reuseable in future applications.
reverse engineering
The process of going from the more concrete level of code to
the more abstract level of models for data and processes.
ROM
Read-only memory. Information is stored once, usually by the
manufacturer, that cannot be changed. Most compact discs are ROM.
root directory
The directory that contains all other directories.
router
A device connecting separate networks that forwards a packet
from one network to another based only on the network address for the protocol
being used. For example, an IP router looks only at the IP network number.
routine
Part of a computer program, or a sequence of instructions
called by a program, that may have some general or frequent use.
routing
The process of finding a path over which a packet can travel
to reach its destination.
run
The single, continuous execution of a program by a computer
on a given set of data. As a verb, to initiate processing by a program.
S
scanner
A device that senses alterations of light and dark.
scheduling
An automated capability to schedule meetings and/or
resources (such as meeting rooms, projectors, etc.) by looking at online
calendars.
screen
The surface of a monitor on which information can be viewed.
screen editor
A program that allows a file to be edited by making changes
to the text displayed on the screen. It may also support commands to make
changes to the whole file at once. Changes to the portion displayed on the
screen are immediately shown.
scroll
To move all or part of the display image vertically or
horizontally to view data otherwise excluded. Scrolling can be performed with a
mouse in the horizontal/vertical bars on each window or by using the page
up/down - home/end - or arrow keys.
segment
A section of network wiring. Segments are connected by
repeaters, bridges or routers.
sequential
A method of storing and retrieving information that requires
data to be written and read sequentially. Accessing any portion of the data
requires reading all the preceding data.
server
A computer that shares its resources, such as printers and
files, with other computers on the network. An example of this is a Network
Files System Server which shares its disk space with a workstation that does
not have a disk drive of its own.
service (or service provider)
An organization that provides access to part of the
Internet. You have to arrange for an account with a service to connect your
computer to the Internet.
session
Networking term used to refer to the logical stream of data
flowing between two programs and being communicated over a network. There may
be many different sessions emanating from any one node on a network.
Session Layer
The fifth layer of the OSI reference model, it provides the
means for two session service users to organize and synchronize their dialogs
and manage data exchange.
shareware
Protected by copyright; holder allows you to make and distribute
copies under the condition that those who adopt the software after preview pay
a fee to the holder of the copyright; derivative works are not allowed; you may
make an archival copy.
shell
A term that usually refers to the user interface of an operating
system. A shell is the command processor that is the actual interface between
the kernel and the user. The C shell or the Bourne shell are the primary user
interfaces on UNIX systems. Contrasts with the kernel, which interacts with the
computer at low levels.
simulation
An imitation of the behavior of some existing or intended
system, or some aspect of that behavior. Examples of areas where simulation is
used include communications network design, weather forecasting and training.
Physical systems can also be simulated, for example, chemical or nuclear
reactions.
smiley
Character combinations such as :-) to denote whether a
message is being made in jest with various modifications thereof ;-) to wink,
etc. Also called emoticons, since not all are smiling %-( .
soft copy
An electronic version of a file, usually in computer memory
and/or on disk; as opposed to hard copy, the paper printout.
software
Computer programs that perform various tasks. Word
processing programs (like WordPerfect or Microsoft Word), spreadsheet programs
(like Lotus or Excel), or database programs (like dBase III+, Foxbase, or
FileMaker) are all software.
software tool
A program that is employed in the development, repair or
enhancement of other programs. Tools include editors, compilers and linkers.
Also refers to utilities, such as formatters and file utilities.
sort
To arrange a set of items in sequence according to keys; for
example, to arrange the records of a personnel file into alphabetical order by
using the employee names as sort keys.
source code
The program in a language prepared by the programmer. This
code cannot be directly executed by the computer and must first be translated
into object code.
SPARC
Scalable Processor ARChitecture. Trademark of
SunMicrosystems 32-bit RISC microprocessor architecture. The architecture is
open in the sense that other vendors can obtain the processor chips and
documentation sufficient to build computers using it.
SPARCstation
A workstation (usually a Sun Microsystems brand) based on
the SPARC chip.
sponge
A job that runs in the background on the IBM 3090 mainframe
computer in such a way that it uses only those CPU cycles not needed by other
work, yet is so computationally intense that it soaks up all unused CPU cycles.
spool
Simultaneous Peripheral Operations On-Line. A scheme that
allows multiple devices to simultaneously write output to the same device such
as multiple computers printing to the same printer at the same time. The data
are actually written to temporary files while a program called a spooler sends
the files to the device one at a time.
spreadsheet
Software program that allows mathematical calculations, such
as budgeting, keeping track of investments, or tracking grades.
SQL
Structured Query Language. ANSI standard data manipulation
language used in most relational data base systems. A language for requesting
data from a relational database.
storage
A device or medium that can retain data for subsequent
retrieval.
strategy
long-term plan, tactic, or scheme for attaining a vision.
string
A sequence of characters.
striping
Disk striping copies blocks, bytes or bits across multiple
disks in such a way that if one disk is lost, the data can be created using the
blocks or bits on the remaining disks.
Sun Microsystems
Sun originally stood for Stanford University Network, a name
given to a printed circuit board developed in 1981 that was designed to run
UNIX.
SunOS
The name of the operating system of the workstation from Sun
Microsystems. It is based on Berkeley UNIX and AT&Ts System V UNIX. It is
composed of three major parts: the kernel and file system, shells and graphical
interfaces, and utility programs.
surfing
Netspeak for wandering, whether one is surfing through cable
stations or surfing the Internet.
T
tape density
A measure of how much data, can fit on a magnetic tape.
task
A separately dispatchable function on a computer.
TCP/IP
Transmission Control Protocol/INTERNET Protocol. The
communication protocols on which the Internet is based.
TEAM
Together Everyone Accomplishes More
telecommunication
Communicating with other people through the computer using
communication software and modems.
telecomputing
Using computers for telecommunication; computer networking.
TELNET
A program that allows users on the Internet to log in to
remote systems from their own host system.
terminal
A device connected to a computer network that acts as a
point for entry or retrieval of information. Personal computers can be made to
act as network terminals, by running terminal emulation (communication)
programs.
terminal emulation
Most communications software packages will permit a personal
computer or workstation to communicate with another computer or network as if
it were a specific type of hardware terminal.
terminal server
A device that allows asynchronous devices such as terminals
to select and then communicate with hosts or other devices over a network.
terabyte
1,099,551,627,776 bytes, often used to mean one trillion
bytes (1,000,000,000,000).
text
A string of characters. A text file should contain only
characters - as opposed to codes or commands.
time out
What happens when two computers are talking and one fails to
respond within a certain time, for whatever reason.
time series.
Observations of a variable made over time. Many economic
studies such as International Financial Statistics, and Citibase are time
series datafiles. Time series, of a sort, can also be constructed from a cross
sectional study if the same questions are asked more than once over time.
TN3270
A version of TELNET providing IBM full-screen support.
toggle
Using one command or keystroke to change between one mode
and its opposite.
token ring
A LAN and protocol in which nodes are connected together in
a ring and communication is controlled by a special packet called a token that
is passed from node to node around the ring. A node can send data only when it
receives the token and the token is not in use. Data is sent by attaching it to
the token. The receiving node removes the data from the token.
topic
In a conference, a message which is generally written to
convey a new idea or a new piece of information, relevant to that conference.
transfer
To copy or move information from one computer to another.
Transport Layer
The fourth layer of the OSI reference model. It provides
transparent, reliable and cost-effective transfer of data.
tree
A way of organizing information with general categories at
the top, subcategories below, and narrower subcategories on a further level.
U
UNIX
A popular computer software operating system used on many
Internet host systems.
upload
To transfer information from a users system to a remote
system. Opposite of download.
URL
Uniform Resource Locater. A scheme used to locate a document
accessible over the Internet.
Usenet
The network of UNIX users, generally perceived as informal
and made up of loosely coupled nodes that exchange mail and messages. Started
by Duke University and UNC-Chapel Hill. An information cooperative linking
around 16,000 computer sites and about 1 million people. Usenet provides a
series of "news groups" analogous to on-line conferences.
user
Anyone who uses a computer connected to the Internet.
user-friendly
A system or program that relatively untrained users can interact
with easily.
userid
A code that uniquely identifies a user and then provides
access privileges to a computer system.
username
Account name or user ID.
utility
A specialized program that performs a frequently required
everyday task such as sorting, report program generation, or file updating.
V
variable
In social science research, for each unit of analysis , each
item of data (e.g., age of person, income of family, consumer price index) is
called a variable.
vision
A future-oriented statement of where you want to be, of what
you want things to be like.
virtual
Pertaining to a device or facility that does not physically
exist, yet behaves as if it does. For example, a system with 4 megabytes of
virtual memory may have only one megabyte of physical memory plus additional
(slower and cheaper) auxiliary memory. Yet programs written as if 4 megabytes
of physical memory were available will run correctly.
virtual terminal
A program that makes a general purpose computer behave like
a terminal.
VMS
Virtual Memory System. An operating system for the VAX and
Alpha computers of Digital Equipment Corporation.
virus
A program that can make a copy of itself without you
necessarily being aware of it; some viruses can destroy or damage files, and
generally the best protection is to always maintain backups of your files
volume
A physical unit of a storage medium, such as tape reel or
disk pack, that is capable of having data recorded on it and subsequently read.
Also refers to a contiguous collection of cylinders or blocks on a disk that
are treated as a separate unit.
W
wavelength
The length of one complete electromagnetic wave, measured
usually from crest to crest or trough to trough of successive vibrations.
whois
The name of the nickname database that contains full name,
postal address, telephone number, and network mailbox for registered users.
Also the name of the local command to access this database, and the name of the
protocol used by this command (RFC-954) that is now an elective draft standard.
window
A rectangular area on a display screen in which part of an
image or file is displayed. The window can be any size up to that of the screen
and more than one window can be displayed at once.
Windows
A trademark of Microsoft Corporation for a software product that
provides an environment for a graphical user interface for DOS and DOS
applications.
word processor
A program used to enter or edit text information in personal
computers, often used to create a file before it is uploaded to a network; may
also be used to process text after it has been downloaded.
wordwrap
An editor feature that causes a word that will not fit on a
line to be moved in its entirety to the next line rather than be split at the
right margin.
work space
Disk space made available to the system to provide temporary
storage space for files too large to fit within a users permanent disk storage
quota or for files not needed beyond a single run of a program or set of
programs.
workstation
A general purpose computer that is small enough and inexpensive
enough to reside at a persons work area for his or her exclusive use. It
includes microcomputers such as Macintosh, and PCs running DOS, as well as
high-performance desktop and deskside computers.
write
To record data in a storage device, a data medium, or an
output display. To save information, especially files, to a disk, to replace
old data with new and permit later access from within a software package; the
complement of read.
WWW
World Wide Web. A wide-area hypermedia information retrieval
technology that interconnects information around the world. It allows you to
travel through the information by clicking on hyperlinks that can point to any
document anywhere on the Internet. Originated at CERN and collaborated upon by
a large, informal, and international design and development team, WWW allows
links inside and between documents, plus pointers to FTP sites, news, telnet
sessions, gopher sites, and WAIS databases.
X
X window system
A standard for controlling the display on a bitmapped
terminal. X-windows normally uses a network connection, and unlike the typical
terminal connection, multiple applications possibly on different computers can
use the display simultaneously in different windows.
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