Types of networks
There are basically two types of networks: Local-Area Networks (LANs) and wide-area networks (WANs). Sometimes, it may be hard to tell the difference, as many LANs themselves connect to other networks or the Internet. In this case, the network as itself will become the Internet.
Regardless of the physical nature of a network, the uses of networks are rapidly changing. Even though networks have primarily been a means of exchanging information and sharing resources, they are so effective that they are increasingly being used for a much larger range of tasks, and some of these tasks are also made possible through networking, thus, the importance of networks is increased dramatically.
Local Area Networks (LANs)
LANs (Local Area Networks) are generally confined to a single office, classroom, or building. LAN connections of computers are usually very fast at transferring data due to the proximity of the computer. A typical LAN will consist of a number of Personal Computers, called workstations, which are linked by wires and cables connected to a larger central computer known as a server. The server would hold data files which can be accessed by users on the network, may act as a "conference table", or even be the means of which a network game could be played. There are also certain cases in which the server holds the software which is used by the workstations. In this case, the workstation is then called a network computer. A good example of this would be the network that is used by a hospital or airport.
For example, collaborative software would allow many people, using different computers, to work together on the same project, like making notes, offering suggestions, correcting errors and even adding insights. This allows everyone's contributions to be immediately visible to all the members of the network, as if they were sitting around a conference table. Thus this collaborative software would change the way in which a computer can be used. Some LANs are conencted to the Internet, or other networks, making them WANS.
Wide-area Networks (WANs)
WANs (Wide Area Networks) may consist of several LANs joined together, or simply a wide area of many users connecting through several networks. They are generally slower than LANs due to the far distance of the computers. One example of this would be the Internet.
Wide-area networks (WANs) are created by enabling computers to send and receive information over much-used forms of communication, such as a telephone line, or sometimes, several fibre-optic lines. The wonderful invention of the modem (modulator/demodulator) plays the most important part in such networks and Wide-area networks are thus literally impossible without the modem. A modem is a small electronic device which converts digital information (information encoded as a series of 1's and 0's ) from a computer into analog (continuous) signals that can travel over telephone lines. It also translates incoming analog telephone signals into digital information for the computer to process for the user. Wide-area networks are mainly used for communication between different parties, the gaining of information, and as a form of cheap communication without having to do international direct dialing. An example of a real large WAN is The Internet
The Internet
The single, most famous and wonderful network ever created, is the Internet. Ultimately, except for networks kept apart mainly for security reasons, all networks may eventually join the single global network known fondly as the Internet. The Internet has a long history. It is originally created by the United States Department of Defense in the 1960s as an emergency communication link in the event of a nuclear fallout, which, will no doubt render any other communication links useless with their Electro-Magnetic Pulse effect. To create a network adaptable to such situations, they had to create a new protocol, TCP/IP. This involved the presence of multiple links to single computers, such that when one part or link of the network went down, other parts would still be functional.
Since then, the Internet has evolved into the largest computer network on Earth! It consists of as many as 50 million computers linked together in the mid-1990's, and the numbers are still increasing at an alarming rate of over 100% per year! The computers hooked into the Internet range from Personal Computers, to huge mainframes at universities, government offices, and corporations. All of them are linked together through the various telephone systems, DSLs, LANs and cable tv.
The Internet enables individuals like you and me to obtain huge amounts of information from all over the world. Any computers that are connected to the Internet can access any information source on the network. It is just like a giant computer with every single known information stored within, shared by everyone all over the world.
Some experts estimate that the information available on the Internet is doubling every few months, and the number of people who have access to the information is also increasing at an equally amazing rate.
"We are witnessing the creation of a global database that may one day contain all of the world's information including artwork, music, and even motion pictures!" - The World Book "Science Year"
In the past, the Internet used to be slow due to the reason that it was connected mainly through modems and thus it was hard then to transfer files of large sizes. However, in the recent years, new technology such as DSL (digital subscriber lines) and cable tv internet connections have made the internet almost as fast as a LAN. The invention of the cellular phone has also enabled many to use the internet while they were on the go!
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