Information Technology Reference
In-Depth Information
Personal Area Networks
A
personal area network (PAN)
consists of devices that directly con-
nect to a single computer. For example, if you are showing a presentation
in a conference room during a business meeting, you might connect your
notebook PC to the projector in the room. You might also form a PAN
by connecting your smartphone to your computer.
personal area network (PAN)
A network
formed when devices are connected to an indi-
vidual computer.
Local Area Networks
A
local area network (LAN)
is a network in which all the devices are
located within the same physical location, such as a single building or
a group of adjacent buildings. A key characteristic of a LAN is that it is
contained within a relatively small area. For example, your home network
is a LAN, and so is the network at your school.
local area network (LAN)
A network that
connects devices housed in the same physical
location.
Metropolitan Area Networks
A
metropolitan area network (MAN)
is a network that spans an entire
town or city—or, as the name implies, a metropolitan area that might
span a major city and its suburbs. A city might invest in a network infra-
structure, for example, and then businesses and individuals within that
area might sign up to use the network.
metropolitan area network (MAN)
A
network that connects devices within the area of
a city or town.
Wide Area Networks
A
wide area network (WAN)
is a geographically dispersed network,
usually consisting of at least two LANs connected together by an exter-
nal link. A business or college with multiple separate campuses might link
all the individual LANs together to form a WAN, for example. A WAN
is not necessarily managed by a single organization and may include
architecture and communications hardware from several different service
providers. In this sense, the Internet is a form of global WAN.
wide area network (WAN)
A network that
spans at least two geographical locations; a busi-
ness with two or more offices may have a LAN at
each site but use a WAN to connect them all to
the same network.
Peer-to-Peer and Client/Server Networks
Another way to classify networks is to look at whether or not a server is
involved in their management. As you learned in Chapter 1, “Computer
Basics,” a
server
is a computer that is dedicated to providing network
and sharing services to the other computers on the network. Very small
networks (10 computers or fewer) can get by without a server by operat-
ing as a
peer-to-peer (P2P) network
, also called a
workgroup.
In a P2P
network, each computer shares in the administrative burden of maintain-
ing the network, as shown in Figure 8.5. Each computer is responsible
for authenticating other users who want to share its resources (files and
printers) and for making those resources available. A P2P network slows
down each computer slightly because of the overhead involved in the
network. It is not usually noticeable with just a few computers, but the
more computers there are, the greater the slowdown.
peer-to-peer (P2P) network
A network that
consists only of clients (no servers).
