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VLAN (Virtual Local Area Network)
A software concept whereby a group of hosts with a common set of requirements
communicate as if they were attached to the same broadcast domain, regardless of
their physical location. A VLAN has the same characteristics as a physical LAN,
but end stations in a VLAN can be grouped together even if they are not located
on the same network switch. Network reconfiguration can be done through soft-
ware instead of physically relocating devices.
VoIP (Voice over Internet Protocol)
A technology that uses Internet Protocol (IP) to transmit telephone calls over the
Internet or a private internal network, rather than using circuit transmissions of
the PSTN. With VoIP, the physical telephone is not necessary; users can com-
municate without a telephone set. A primary attraction of VoIP is its ability to
reduce expenses, since telephone calls travel over the data network rather than the
phone company's network.
WAN (Wide Area Network)
A computer network that covers a broad area (e.g., any network that links across
metropolitan, regional, or national boundaries). WANs are similar to the Internet
in that they are not owned by a single organization. They exist under collective or
distributed ownership and management. For WAN connectivity over the longer
distances, ATM, frame relay, and X.25 are used. Computers connected to a WAN
can be connected via the telephone system, leased lines, or satellites. WANs have
a lower data transfer rate when compared to LANs. See also "LAN."
xML (extensible Markup Language)
A flexible way to create common information formats and share both the format
and the data on the Internet, intranets, etc. XML and HTML are similar, in
that they both contain markup symbols to describe the contents of a page or file.
However, HTML focuses on how data looks, whereas XML focuses on what data
is. In HTML, text that is placed between markup tags <TITLE> and </TITLE>
will simply take on the appearance (font, size, etc.) of a "title tag." However, if
the same text were placed between XML markup tags <book_title> and </book_
title>, it would likely mean that the data was a title of a book. Then depending
on how the application in the receiving computer wanted to handle the book
title, it could be stored or displayed on a website with a selection of other books
that can be purchased.
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