|
Term |
Definition |
| Data |
Raw or unorganised facts and figures |
| Data dictionary |
A specialized type of database containing metadata (data about
data), which is managed by a data dictionary system; a repository of
information describing the characteristics of data used to design, monitor,
document, protect, and control data in information systems and databases; an
application of data dictionary systems. |
| Data encryption |
Encypting data is accomplished by applying a special scrambling
code that makes the data unreadable to anyone who does not have a decryption
key. Authorized personnel with access to this key can unscramble it. Data
encryption is a useful tool against network snoopers. |
| data entity |
an entity that has of may have a data value. It may be a constant,
a variable, an expression or a function result. |
| data redundancy |
The storage of duplicate data. Data redundancy is often unnecessary
but is sometimes useful or essential. relational databases help reduce the
unnecessary replication of data. Unique keys in each database table are used to
link tables of data belonging to specific records or entries in the
database. |
| Database |
software that allows tables of data to be built |
| DBMS |
DataBase Management System. An advanced database that has a good
user interface, is capable of being used by several users at once, provides
backup recovery, a data dictionary and the potential to link tables. |
| DDE |
(Dynamic Data Exchange) An interposes communication (IPC) system
built into the Macintosh, Windows, and OS/2 operating systems. DDE enables two
running applications to share the same data. For example, DDE makes it possible
to insert a spreadsheet chart into a document created with a word processor.
Whenever the spreadsheet data changes, the chart in the document changes
accordingly. Although the DDE mechanism is still used by many applications, it
is being supplanted by OLE, which provides greater control over shared
data. |
| De facto standard |
A format, language, or protocol that has become a standard not
because it has been approved by a standards organisation but because it is
widely used and recognised by the industry as being standard. |
| DE Jure Standard |
Standard that exist because of its approval by an official
standards body. Compare with de facto standard. See also standard. |
| DES |
"Data encryption Standard An encryption standard developed by IBM
and then tested and adopted by the National Bureau of Standards. Published in
1977, the DES standard has proven itself over nearly 20 years of use in both
government and private sectors. Currently DES is the US government standard
tool for encrypting non-classified data." |
| Digerati |
The digital version of literati, it is a reference to a vague cloud
of people seen to be knowledgeable, hip, or otherwise in-the-know in regards to
the digital revolution. |
| Digital signal |
A digital signal has a time structure which allows discrete symbols
to be represented by a parameter or feature of the signal. Distortion of the
signal in the channel does not necessarily result in loss of information. |
| Disaster recovery |
The documented process for protecting and restoring critical
information during emergency or disaster conditions, such as the loss of a
computer facility. Disaster recovery management involves many functions, such
as identifying critical and vital information; determining recovery needs,
developing backup solutions and implementing the backup/recovery solution. |
| Dispersed Systems |
User software that runs on several machines at once. |
| Distributed processing |
1. Where local processors handle data in a WAN. 2. Can be a cheep
way of processing complex data locally on cheep computers e.g.. PCs (see
heathcote page 316) |
| Distributed Systems |
Arrangements wherein an organization's computer complex has many
separate computing facilities interfaced and working in a cooperative
manner. |
| Domain |
An Internet domain refers to a networked computer accessible
through a host, or domain, name. |
| Domain Name |
The unique name that identifies an Internet site. Domain Names
always have 2 or more parts, separated by dots. The part on the left is the
most specific, and the part on the right is the most general. A given machine
may have more than one Domain Name but a given Domain Name points to only one
machine. For example, the domain names: |
| Domain name suffixes |
A domain identity includes a distinguishing suffix. Some important
domains suffixes are: .com (commercial), .edu (educational, primarily in the
U.S.), .net (network operations), .gov (government), and .mil (US military).
Most countries also have a domain. For example, .us (United States), .uk
(United Kingdom), .au (Australia). Within the Within the .uk domain, there is a
.ac.uk subdomain for academic sites and a .co.uk domain for commercial
sites. |
| dongle |
A small connector plugged into a computers parallel port, used as a
copy-protection device. Some expensive software wont run unless its specific
dongle is plugged in. |
| DPA |
Data Protection act |
| DSL |
(Digital Subscriber Line) -- A method for moving data over regular
phone lines. A DSL circuit is much faster than a regular phone connection, and
the wires coming into the subscribers premises are the same (copper) wires used
for regular phone service. A DSL circuit must be configured to connect two
specific locations, similar to a leased line. |
| DTP |
Desk top publishing |
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