Dell OptiPlex GX50, User Manual

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in the United States, many customers of large manufacturers make UL
approval a mandatory requirement.
UPS
Uninterruptible power supply. A device that allows your computer to keep
running for a limited amount of time after the primary power source is lost.
Typically, a UPS can also provide protection against power surges.
URL
Uniform Resource Locator . A standard way of specifying the location of an
object, such as an HTML document, on the Internet. Examples of URLs
include the following:
• http://www.dell.com
• http://support.dell.com
• ftp.dell.com
• mailto:info@dell.com
The part before the first colon specifies the access scheme or protocol.
Commonly implemented schemes include FTP and http . The part after the
colon is interpreted according to the access scheme and can introduce an IP
address , indicate a path or file on a server, or locate a particular position within
a specified document.
USB
Universal Serial Bus . An interface for devices such as keyboards, joysticks,
scanners, speakers, or printers, that provides a maximum transfer speed of
12 Mb /second. Devices plug directly into a four-pin connector on your
computer or into a multiport hub that connects to your computer. USB is
hot-swappable , and up to 127 devices can be connected in daisy-chain
manner.
UTP
Unshielded twisted pair . A common type of copper wiring used for telephone
systems and Ethernet networks. To reduce electromagnetic induction
between pairs of wires, sometimes called “crosstalk,” two insulated copper
wires are wound around each other to form a “twisted pair.” See also STP .
V
Volt . A measurement of electric potential and electromotive force. If one volt
is applied to a resistance of one ohm, a current of one ampere will flow across
the resistance.
VAC
Volt(s) alternating current ( AC )
.