National Teaching and Learning Change ProgrammeInformation and Communication Technology:
Dictionary

• Home
• Data representation
• General
• Hardware
• Internet/web
• Managing data
• Multimedia
• Networks and communications technology
• Programming
• Security
• Software
• Systems design
• My downloads

Search results

• date data
  A type of data used to represent a date, for example 01/02/2007 or 1st February 2007.
• 
• datum
  The singular of data. The raw material of information.
• 
• debug
  This is the process of testing that programs work correctly, and correcting any errors found.
• 
• decimal
  A numbering system using base 10, and the digits 0 to 9. This is the numbering system commonly used by people.
• 
• decimal point
  In a decimal number, the dot separating the whole number on the left from the fractional part on the right.
• 
• declare a variable
  In programming, to declare something is to define the name and data type of a variable, array, or some other similar object in programming. Many, but not all, programming languages require you to declare variables before using them.
• 
• decode
  Similar to decrypt, i.e. decrypting data so that it can be read after it has been encrypted or encoded.
• 
• decrement
  To reduce something by one unit.
• 
• decryption
  Encryption makes data in a computer system unintelligible without a decryption key. The encrypted data appears to be meaningless and is sometimes described as scrambled data. Encryption provides security for the data (by preventing it being understood), both when stored electronically and when transmitted between computer systems. Decryption is converting the unreadable data back into an understandable form.
• 
• default
  Settings in computer hardware or software which are the ones used unless the user explicitly changes them.
• 
• default settings
  A general term describing the values which something has originally, e.g. one of the default settings for a word processor would be the language (used for the dictionary and spell checking) that it was set to when it was first installed. Default settings can usually be changed by the user.
• 
• defragment
  After a hard disk has been used for a while, the files on it may become split up and different parts of the same file may be stored in different places on the disk - i.e. fragmented. This slows down disk operations. Defragmenting a disk is when these separate parts are collected together again, so speeding up the disk accesses.
• 
• delete
  The process of removing a file from a disk, or erasing characters or other data.
• 
• delete key
  A key which deletes characters.
• 
• demo version
  A sample program used to demonstrate the full features of the program.
• 
• descendant
  In a tree data structure, a descendant is a node which is linked to another node at a higher level.
• 
• desk top publishing (DTP)
  This is similar to word processing except that it offers more facilities for layout and design.
• 
• desktop
  The term for the main workspace on the screen in most graphical user interfaces (GUIs). Users open and work with files and programs on the desktop, and can store files and shortcuts there. The user can usually customise the look of the desktop with images or wallpaper, icons, etc.
• 
• desktop computer
  A desktop computer is used at a desk as a tool for the individual user, and has a full sized screen and keyboard. It needs a mains power supply. The box containing the central processor, disk drives and other storage sometimes provides the support for the monitor; however, the box may be in the shape of a tower designed to stand on the floor by a desk or be small enough to stand on the desk beside the monitor, when it is called a mini-tower.
• 
• destination address
  The address to which a packet of data is to be sent.