|
Term
|
Description
|
|
Default
|
That
which is chosen by the Operating System or program if the user
doesn't specify something different.
E.g. default drive, default printer,
default directory, etc..
|
|
Defragment
|
Your
computer can slow down when files become fragmented. This means
that the clusters the file is stored in are not physically next
to each other on the disk. The read/write heads have to travel
further to read the file. By defragmenting, files are rewritten
to the disk in contiguous clusters thus speeding up data retrieval. |
|
Desktop
|
When
an Operating System that uses a Graphical User Interface (GUI)
is finished loading, the screen that is initially displayed is
called the Desktop. When you run a program or open a folder it
appears in a window on the Desktop. |
|
Device
Driver
|
Individual
programs can access communication ports or expansion slots either
directly or via the OS or BIOS. However, there is such a vast
number of different devices available to hook up to your computer
that it can't be expected to know how to use the features of all
of them. Most devices are shipped with small programs that are
loaded onto your hard drive and tell the computer how to communicate
with that specific input/output device whether it be a modem,
printer, video card, etc.. These small software programs are called
Drivers and are specific to each make and model of the device
it comes with. |
|
Diffuse
|
A
technique to create a gray-scale image. Pixel patterns aren't
set; they change gradually throughout the image. |
|
DIMM
|
Dual
Inline Memory Module. A small printed circuit board with memory
chips on it. These modules clip into sockets on the motherboard
to make up your system RAM. They come in denominations of 16,
32, 64, and 128 MB. |
|
DIP Switch
|
A
small switch on a circuit board or some other device that holds
configuration or setup information for that device. |
|
Directory
|
A
table made by the Operating System that contains file information
such as file name, size, date created, and the file's beginning
cluster number. |
|
Display
Adapter
|
An
adapter board or interface card that fits into a slot on the motherboard
and controls the video signal sent to the monitor. |
|
Dither
|
To
create a gray-scale image by using fixed patterns of black and
white pixels to represent each shade of gray. Every time the image
needs a particular shade of gray, the software uses the same pattern. |
|
DLL
|
Dynamic
Link Library. A file that contains several small programs or routines
that are common to many programs such as opening a window or saving
a file. These library files have a .dll extension. |
|
DMA
|
Direct
Memory Access is an electronic pathway or direct channel on which
a device can bypass the CPU and send data directly to memory.
A DMA channel is often one of the resources assigned when configuring
an expansion card or device such as a sound card. |
|
Documentation
|
Manuals,
tutorials, and Help files that provide information that a user
needs in order to use a computer system or software application. |
|
Domain
|
On
TCP/IP networks, such as the Internet, a domain is a group of
connected computers. Domains are identified on the Internet by
a two or three letter code. Some of the most common are: .com
- commercial site, .edu - educational institution, .gov - government
site, .net - network site, .org - non-profit or private organization,
.ca - a Canadian site. A domain can also refer to a group of workstations
on a network. There can be sub-domains within a domain. |
|
Domain
Name
|
An
identifying name given to a system or group of computers on a
network. For example, the domain name computerstuff.com indicates
that the domain is a commercial site (.com) and that the sub-domain
name is computerstuff. |
|
Dot Pitch
|
The
distance between pixels of the same color on a monitor screen. |
|
DRAM
|
Dynamic
Random Access Memory. The most common type of system RAM. It comes
in several different flavors, EDO, FPM, SDRAM. It uses less space,
less power, and is cheaper than static RAM, but it has to be refreshed
every millisecond or it loses its information. |
|
Driver
|
See
Device Driver. |
|
DriveSpace
|
DriveSpace
is a Microsoft utility that is supposed to increase the amount
of space on your hard drive. What it actually does is compress
the files on your drive and create a single large file that contains
all the compressed. The compression and decompression takes place
in the background, unnoticeable to the user. |
|
Dual Boot
|
The
ability to boot your computer using one of two different operating
systems. |
|
Dual Voltage
CPU
|
A
Central Processing Unit that requires two different voltages,
one for external functions and one for internal processing. |
|
DVD
|
Digital
Video Disk. A type of CD-ROM format that is faster and can hold
more data than a regular CD-ROM. It still has the ability to read
older CDs, but a DVD disk can hold more than 8 gigabytes (as opposed
to 750 Mb) and can display full-motion picture videos. |
|
Dynamic
RAM
|
See
DRAM. |
