Dell GX620 - 3.6GHz Desktop 1GB RAM 80GB Windows XP SFF, User Manual

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Glossary 311
password. Unless you understand what effect the settings
have on the computer, do not change the settings for this
program.
S Y S T E M T R A Y
— See notification area .
T
TA P I — telephony application programming interface —
Enables Windows programs to operate with a wide variety
of telephony devices, including voice, data, fax, and video.
T E X T E D I T O R
— A program used to create and edit files
that contain only text; for example, Windows Notepad uses
a text editor. Text editors do not usually provide word wrap
or formatting functionality (the option to underline, change
fonts, and so on).
T R A V E L M O D U L E
— A plastic device designed to fit
inside the module bay of a portable computer to reduce the
weight of the computer.
U
U P S — uninterruptible power supply — A backup power
source used when the electrical power fails or drops to an
unacceptable voltage level. A UPS keeps a computer
running for a limited amount of time when there is no
electrical power. UPS systems typically provide surge
suppression and may also provide voltage regulation. Small
UPS systems provide battery power for a few minutes to
enable you to shut down your computer.
U S B — universal serial bus — A hardware interface for a
low-speed device such as a USB-compatible keyboard,
mouse, joystick, scanner, set of speakers, printer, broadband
devices (DSL and cable modems), imaging devices, or
storage devices. Devices are plugged directly in to a 4-pin
socket on your computer or in to a multi-port hub that plugs
in to your computer. USB devices can be connected and
disconnected while the computer is turned on, and they can
also be daisy-chained together.
U T P — unshielded twisted pair — Describes a type of
cable used in most telephone 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.
U X G A — ultra extended graphics array — A video
standard for video cards and controllers that supports
resolutions up to 1600 x 1200.
V
V I D E O C O N T R O L L E R
— 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.
V I D E O M E M O R Y
— 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.
V I D E O M O D E
— 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.
V I D E O R E S O L U T I O N
— See resolution .
V I R U S
— 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