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Glossary
D
DDR SDRAM
Internal devices (below) in a computer execute a variety of operations using a clock signal that
turns on and off repeatedly at fixed intervals. SDRAM (Synchronous DRAM) is a type of mem-
ory that operates in synchronous with this clock cycle (
). DDR SDRAM (Double-
data-rate synchronous DRAM) uses twice the data transmission speed of the standard
SDRAM.
Designed for Microsoft
®
Windows
®
XP logo
This mark is affixed to products that have been certified to meet computer device standards,
tested according to standards defined by Microsoft, and confirmed to enable use of new
functions incorporated into Windows XP.
Device
A general term for peripheral equipment connected to the computer, such as a keyboard or
external hard disk. The term “Device” also refers to components built into the computer itself,
such as the hard disk drive, modem, or LAN.
Dithering
Displaying an intermediate color tone by combining several colors. For example, one form of
dithering is to create a gray image by lining up alternating black and white pixels.
Double Click
Pressing and releasing the mouse button or touch pad twice in quick succession to display data
or execute a program or menu. The right mouse button is used to execute a double click.
Drag
The mouse button is held down while the mouse is moved to select regions, or to move
selected icons or windows. In the case of the touch pad, the drag operation can be executed
by moving the finger across the pad surface while the mouse button is depressed.
Driver
Software that provides the OS with information about a connected peripheral device (what type
of product it is, and how it should be operated), so that the OS can operate that device properly.
This software is also called a “device driver”. The drivers for some peripheral devices are
included in Windows, but when the driver is not included, it must be installed in order to use the
device.
