Dell PowerEdge R900 - Manual (Page 181)

Glossary 181
by changing settings in the configuration software for the devices.
UNIX — An operating system written in the C programming language. A precursor to
Linux.
U P L I N K P O RT
— A port on a network hub or switch used to connect to other hubs or
switches without requiring a crossover cable.
UPS — Uninterruptible power supply. A battery-powered unit that automatically
supplies power to your system in the event of an electrical failure.
USB — Universal Serial Bus. A USB connector provides a single connection point for
multiple USB-compliant devices, such as mice and keyboards. USB devices can be
connected and disconnected while the system is running.
U T I L I T Y
— A program used to manage system resources—memory, disk drives, or
printers, for example.
UTP — Unshielded twisted pair. A type of wiring used to connect systems in a
business or home to a telephone line.
V — Volt(s).
VAC — Volt(s) alternating current.
VDC — Volt(s) direct current.
VGA — Video graphics array. VGA and SVGA are video standards for video adapters
with greater resolution and color display capabilities than previous standards.
VI DE O A D A P TE R
— The logical circuitry that provides (in combination with the
monitor) your system’s video capabilities. A video adapter may be integrated into the
system board or may be an expansion card that plugs into an expansion slot.
VI DE O D R I V E R
— A program that allows graphics-mode application programs and
operating systems to display at a chosen resolution with the desired number of colors.
Video drivers may need to match the video adapter installed in the system.
VI DE O M E M O R Y
— Most VGA and SVGA video adapters include memory chips in
addition to your system’s RAM. The amount of video memory installed primarily
influences the number of colors that a program can display (with the appropriate video
drivers and monitor capabilities).
VI DE O R E SO L U T I O N
— Video resolution (800 x 600, for example) is expressed as the
number of pixels across by the number of pixels up and down. To display a program at
a specific graphics resolution, you must install the appropriate video drivers and your
monitor must support the resolution.