318
I
Integrated Services Digital Network (ISDN):
A worldwide communications network for
delivering telephone and data services. It uses two types of communications
channel: a B channel, which carries voice, graphics and data at 64 Kbps, and a
D channel, which carries control information for signalling at 16 Kbps. A basic
ISDN installation typically provides two B channels and one D c
hannel
.
Internet:
The collection of computers located throughout the world that are connected
over telephone lines to provide electronic mail and other services.
intranet:
World Wide Web pages designed to serve a limited group of people, such as the
employees of a particular company.
IP address:
The Internet Protocol address is a unique number for the server and each
client computer on a network.
L
LAN
(Local Area Network):
A collection of computers (located geographically close to
each other) connected together in a network.
light-emitting diode (LED):
A semiconductor device that emits light when it receives an
electric current. Used for indicators like disk activity lights.
liquid crystal display (LCD):
A type of display that uses a liquid substance between two
transparent electrode panels. By selectively turning the electrodes on and off,
the LCD creates the images you see on the screen.
M
map
: A method of associating objects or of translating one set of values into another. For
example, the association of logical drive letters with the actual physical
devices.
modem:
A device for transmitting computer information over telephone lines. A modem
converts (modulates) digital information for transmission and also converts
(demodulates) information it receives back to digital format. Many modems
also interpret and execute commands received from the computer.
