1.0 INTRODUCTION An interconnected set of two or more computers with data communication devices may be called a computer network. The wired arrangement consists of a communication software (Network Operating System), computer systems (Nodes), Network interface cards (connectors) and network cable (medium). 2.0 OBJECTIVES At the end of this unit, you should be able to: • state the principles of Networking • explain Local Area Network • explain Wide Area Network • explain what internet is • explain what is World Wide Web. The objective of this section of Module 6 is to give you a brief overview of the principles of Networking. 3.0 MAIN CONTENT 3.1 Terminology You will hear talk of LAN, MAN, WAN and WWW. This is often confusing, but let’s attempt to define the terms: LAN Stands for Local Area Network and refers to a network set up in one building. MAN is a Metropolitan Area Network and refers to two LANs linked between two buildings in the same metropolis. WAN is a Wide Area Network and refers to LANs or MANs that are connected between cities. WWW is a World Wide Web and refers to the linking up the world’s LANs, MANs and WANs to form a web of networks that cover the earth. 3.1.1 Networks When two or more computers are interconnected this is generally referred to as a network. Networks have become increasingly popular over the last decade. There are a various reasons for this phenomenon. The two main reasons are firstly convenience, and secondly cost savings. Networks can be used to transfer information between computers, even if they use different operating systems. A network can also be used to send data to remote storage devices and printers, without having to send all of the signals through an expensive mainframe computer. Generally networks provide an inexpensive way to interconnect any number of systems and make communication and sharing of data quick and easy. There are two main categories of networks used in the industry, which are LAN’s (Local Area Network) and WAN’s (Wide Area Network). 3.2 Local Area Network (LAN’s) A LAN is a network in which all signals run on a single set of cables, which is fully administered by the owner. There are three typical network topologies (layouts). These are star, ring and bus shapes. The star shape is the most common. Here outlying stations communicate through a central hub device.