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Information Security and Privacy

Notes
!
Caution In addition to not wasting storage, having the databases in one place avoids
problems with inconsistent data.

Local area networks normally use coaxial cables to connect the computers together. Two or
more computers connected together can share, besides data, their peripherals such as printers,
modems, etc. This cuts down a lot on the hardware equipment cost.
Besides coaxial cables, a plug-in card is also required for each computer. The coaxial cables
connect the plug-in cards of the computers to form a network. A special software is also required
for the network to operate.
All local area networks transfer data in digital form at a high speed and have a low
implementation cost.
Some applications performed by a LAN are as follows:
1. File transfer and access

2. Accessing the internet
3. Providing Management Information System.

Figure 7.1: Local Area Networks

7.2.2 Wide Area Networks (WANs)

A wide area network connects computers which are very remotely placed. It may connect across
the countries or continents or the entire globe.
Wide area networks can either be point to point type or broadcast type. In a point to point type
network, the source and the destination machines are connected to each other via several
intermediate routers. A point to point type network may be separated into two parts — the hosts
and the subnet.
The machines between which communication is to be established are called hosts. The hosts are
connected to each other by what is known as the subnet. The subnet consists of the transmission

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