DSL service, which is available from telephone companies in
many parts of the United States, uses a sophisticated modulation
scheme to move data over the wires without interfering with
voice traffic.
Digital video disk SeeDVD.
Direct access file A basic type of computer file from which it is
possible for the computer to obtain a record immediately, without
regard to where the record is located on the file; usually stored on
magnetic disk. Computer files, also called secondary memory or
secondary storage, are added to a computer system to keep vast
quantities of data accessible within the computer system at more
reasonable costs than main memory.
Direct access storage device (DASD) The device on which
direct access files are stored. See alsoDirect access file.
Direct Distance Dialing (DDD) The normal way of using the
long-distance telephone network in the United States in which
the user directly dials the number with which he or she wishes to
communicate and pays for the service based on the duration of
the call and the geographical distance; may be used for voice
and data communications between any two spots served by the
telephone network.
Disposable application An application that can be discarded
when it becomes obsolete without affecting the operation of any
other application; this is made possible by application
independence. Also referred to as a disposable system. See also
Application independence.
Distributed data processing SeeDistributed systems.
Distributed systems Application systems in which the pro-
cessing power is distributed to multiple sites, which are then tied
together via telecommunications lines. Distributed systems have
computers of possibly varying sizes located at various physical
sites at which the organization does business, and these com-
puters are linked by telecommunications lines in order to support
some business process.
Documentation Written descriptions produced during the
systems development process for those who use the system (user
documentation) and for IS specialists who operate and maintain
the system (system documentation).
Dot-com A term used to describe a cyber business that
receives revenues entirely based on customer transactions or
other usage of its Web site. Also referred to as a “pure-play”
dot-com business, as distinguished from a “bricks-and-clicks”
business.
DSL SeeDigital Subscriber Line.
DSS SeeDecision support system.
DSS generator Computer software that provides a set of
capabilities to build a specific DSS quickly and easily. For
example, Microsoft Excel, a spreadsheet package, can be used as
a DSS generator to construct specific financial models that can be
used in decision making.
DVD An abbreviation for digital video disk, an optical storage
device that holds much more data than a conventional CD and
therefore can be used for very large files such as video; standard
capacity varies from 4.7 gigabytes up to 17 gigabytes. Also called
a digital versatile disk. See alsoCD, Optical disk.
E-business systems Applications that enable the electronic
transmission of business transactions or other related information
between a buyer and seller or other business partners. See also
B2B, B2C.
E-commerce SeeElectronic commerce.
E-crime SeeComputer crime.
E-mail SeeElectronic mail.
EDI SeeElectronic data interchange.
eDiscovery amendments Amendments to the U.S. Federal
Rules of Civil Procedure effective December 2006 that establish
procedures for records retention and electronic information
gathering that U.S. organizations must follow in response to
potential litigation as well as penalties for noncompliance.
EDP auditing A variety of methods used by trained auditors to
ensure the correct processing of data. EDP auditing combines
data processing controls with classical accounting auditing
methods.
EIS SeeExecutive information system.
Electronic commerce The electronic transmission of
buyer/seller transactions and other related communications
between individuals and businesses or between two or more
businesses that are trading partners. By the late 1990s the Internet
became the major platform for conducting electronic commerce
or e-commerce. See alsoB2B, B2C, Dot-com.
Electronic data interchange (EDI) A set of standards and
hardware and software technology that enable computers in
independent organizations to exchange business documents
electronically. Although typical transactions include purchase
orders, order acknowledgments, invoices, price quotes, shipping
notices, and insurance claims, any document can potentially be
exchanged using EDI. The transaction standards are typically
established by an industry consortium or a national or inter-
national standards body (such as ANSI).
Electronic mail A system whereby users send and receive
messages electronically at their workstations. Electronic mail, or
e-mail, can help eliminate telephone tag and usually incorporates
such features as sending a message to a distribution list, resend-
ing a message to someone else with an appended note, and filing
messages in electronic file folders for later recall.
Electronic records management (ERM) A disciplined
approach to managing electronic records (including e-mail docu-
ments) for efficient storage and retrieval over their useful life
cycle, including the establishment and enforcement of time
periods for records retention and destruction.
Encapsulation A principle of object-oriented modeling and
programming in which both data and operations (methods) to be
performed using the data are stored together as an object.
Encryption An encoding system used for transmission of
computer data to ensure confidentiality and security of the data.
End-user computing SeeUser computing.674 Glossary