Dell Latitude D631 (Early 2009) User Manual

Page 163

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Glossary

163

for this program.

T

TAPI — telephony application programming interface —

Enables Windows programs to operate with a wide variety

of telephony devices, including voice, data, fax, and video.
text editor — 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).
TPM — trusted platform module — A hardware-based

security feature that when combined with security

software enhances network and computer security by

enabling features such as file and e-mail protection.
travel module — A plastic device designed to fit inside

the module bay of a portable computer to reduce the

weight of the computer.

U

UAC — user account control— Microsoft Windows

Vista

®

security feature that, when enabled, provides an

added layer of security between user accounts and access

to operating system settings.
UMA — unified memory allocation — System memory

dynamically allocated to video.
UPS — 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.
USB — 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.
UTP — 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.
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

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