Laptop User Manual

User’s Manual Glossary-3
L550/L550D/L555/L555D
A
adaptor: A device that provides a compatible connection between two
units. For example, the computer’s internal display adapter receives
information from the software and translates it into images on the
screen. An adapter can take a number of forms, from a
microprocessor to a simple connector: An intelligent adapter (one
that is capable of doing some processing) may also be called a
controller.
alphanumeric: Keyboard characters including letters, numbers and other
symbols, such as punctuation marks or mathematical symbols.
alternating current (AC): Electric current that reverses its direction of flow
at regular intervals.
analog signal: A signal whose characteristics such as amplitude and
frequency vary in proportion to (are an analog of) the value to be
transmitted. Voice communications are analog signals.
application: A group of programs that together are used for a specific task
such as accounting, financial planning, spreadsheets, word
processing and games.
ASCII: American Standard Code for Information Interchange. ASCII code is
a set of 256 binary codes that represent the most commonly used
letters, numbers, and symbols.
asynchronous: Lacking regular time relationship. As applied to computer
communications, asynchronous refers to the method of transmitting
data that does not require a steady stream of bits to be transmitted
at regular time intervals.
B
backup: A copy of a file, usually on a removable disk, kept in case the
original file is lost or damaged.
binary: The base two number system composed of zeros and ones (off or
on), used by most digital computers. The right-most digit of a binary
number has a value of 1, the next a value of 2, then 4, 8, 16, and so
on. For example, the binary number 101 has a value of 5. See also
ASCII.
BIOS: Basic Input/Output System. The firmware that controls data flow
within the computer. See also firmware.
bit: Derived from “binary digit,” the basic unit of information used by the
computer. It is either zero or one. Eight bits is one byte. See also
byte.
Bluetooth: A short-range radio technology designed to simplify wireless
communication among computers, communication devices and the
Internet.