Basic Computer Networks.

computer network is a set of connected computers. Computers on a network are called nodes. The connection between computers can be done via cabling, most commonly the Ethernet cable, or wirelessly through radio waves. Connected computers can share resources, like access to the Internet, printers, file servers, and others. A network is a multipurpose connection, which allows a single computer to do more.

Types of Computer Networks

Different types of private networks are distinguished based on their sizes (in terms of the number of machines), their data transfer speeds, and their reach. Private networks are networks that belong to a single organization. There are usually said to be three categories of such networks: LAN, or local area networkMAN, or metropolitan area network; and WAN, or wide area network.


LAN refers to a group of computers that all belong to the same organization and that are linked within a small geographic area using a network and often the same technology (the most widespread being Ethernet).

A local area network is a network in its simplest form. Data transfer speeds over a local area network can reach up to 10 Mbps, such as for an Ethernet network, and 1 Gbps, as with FDDI or Gigabit Ethernet. A local area network can reach as many as 100, or even 1000, users.

MANs connect multiple geographically close LANs (over an area of up to several dozen miles) to one another at high speeds. Thus, a MAN lets two remote nodes communicate as if they were part of the same local area network.

A MAN is made from switches or routers connected to one another with high-speed links (usually fibre optic cables).


A WAN connects multiple LANs to one another over great geographic distances. The speed available on a WAN varies depending on the cost of the connections, which increases with distance, and may be low.

WANs operate using routers, which can “choose” the most appropriate path for data to take to reach a network node.

The most well-known WAN is the Internet.

There are two other types of networks: TANs, or Tiny Area Network, which are the same as LANs but smaller, consisting of 2 to 3 machines; and CANs, or Campus Area Networks, which are the same as MANs, with bandwidth limited between each of the network’s LANs.

Lesson tags: Tec001
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