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Dell Latitude D530 (Early 2008) User Manual

Page 175

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Glossary

175

networks and some computer networks. Pairs of unshielded wires are twisted to protect

against electromagnetic interference, rather than relying on a metal sheath around

each pair of wires to protect against interference.
UXGA — ultra extended graphics array — A video standard for video cards and

controllers that supports resolutions up to 1600 x 1200.

V

video controller — The circuitry on a video card or on the system board (in computers

with an integrated video controller) that provides the video capabilities—in

combination with the monitor—for your computer.
video memory — Memory that consists of memory chips dedicated to video functions.

Video memory is usually faster than system memory. The amount of video memory

installed primarily influences the number of colors that a program can display.
video mode — A mode that describes how text and graphics are displayed on a

monitor. Graphics-based software, such as Windows operating systems, displays in

video modes that can be defined as x horizontal pixels by y vertical pixels by z colors.

Character-based software, such as text editors, displays in video modes that can be

defined as x columns by y rows of characters.
video resolution — See resolution.
virus — A program that is designed to inconvenience you or to destroy data stored on

your computer. A virus program moves from one computer to another through an

infected disk, software downloaded from the Internet, or e-mail attachments. When

an infected program starts, its embedded virus also starts.
A common type of virus is a boot virus, which is stored in the boot sectors of a floppy

disk. If the floppy disk is left in the drive when the computer is shut down and then

turned on, the computer is infected when it reads the boot sectors of the floppy disk

expecting to find the operating system. If the computer is infected, the boot virus may

replicate itself onto all the floppy disks that are read or written in that computer until

the virus is eradicated.
V — volt — The measurement of electric potential or electromotive force. One V

appears across a resistance of 1 ohm when a current of 1 ampere flows through that

resistance.

W

W — watt — The measurement of electrical power. One W is 1 ampere of current

flowing at 1 volt.
WHr — watt-hour — A unit of measure commonly used to indicate the approximate