D
1. Data Transfer Rate
The speed at which data can be read from the hard disk and delivered to the processor.
2. Default value
A number of programs will require the user to provide information. In some cases if the user chooses not to enter a value a “default value” will be taken. If for instance you have a database in which you record the names and addresses of all your customers and nearly all of them are based in the UK you can set the database up such that if a country is not entered then it will be defaulted to the UK.
3. DMA (Direct Memory Access)
A DMA channel is used to transmit data at a high speed between an I/O device and the PC’s memory without involving the microprocessor.
4. DMI (Desktop Management Interface)
Software for managing the PC’s within a network from a central PC.
5. Dot Pitch
A measure of the space between pixel’s displayed on the monitor.
6. DPI (Dots per inch)
A measure of the quality of the output from a printer- the greater the number of DPI the better the printer.
7. DVD (Digital Video Disk)
DVD can hold over 4 gigabytes of information- these are predicted to eventually supersede CD’s.
8. Debugging
It is the process of eliminating errors in a program. Its objective is to detect the cause of error and remove known errors in the program. Debugging is complete when all known errors in the program are fixed. It ends temporarily and restarts whenever new errors are detected in the program.
9. DDL (Data Definition Language)
A language used to define the structure of a database.
10. DTP (Desktop Publishing)
An application software package that enables a user to perform design, typesetting, and paste-up functions, and to produce high-quality, camera-ready printed pages of the documents so prepared on a high-quality printer.
11. Disk array
A mass storage device that uses a set of hard disks, hard disk drives, and a controller mounted in a single box forming a single large storage unit. Also known as Redundant Array of Inexpensive Disks (RAID).
12. Dumb Terminal
A display monitor that has no processing capabilities. A dumb terminal is simply an output device that accepts data from the CPU. In contrast, a smart terminal is a monitor that has its own processor for special features, such as bold and blinking characters. Dumb terminals are not as fast as smart terminals, and they do not support as many display features, but they are adequate for most applications.
13. DDE (Dynamic Data Exchange)
Technique for linking applications to enable users to move data from one application to another such as’ from a spreadsheet to a word-processor. Changes made in one application are reflected automatically in linked applications.
14. DRAM (Dynamic RAM)
A type of RAM that uses an external circuitry to periodically “regenerate” or refresh the storage charge to retain the stored data.
15. Dial up line
Also known as switched line service operates like a telephone service. That is, a user of a computer willing to communicate with a remote computer first makes a connection request by dialing up the remote computer. A circuit is then established between the two computers via telephone company’s switching system. Modems attached to the computers then send and receive data over telephone line. Like a telephone call, charge for data transmission service in this case depends on duration of communication (circuit establishment), and distance between two computers.
16. Downtime
The time interval during which a device is malfunctioning or inoperative.
