IntroductionA wide area network is a geographically dispersed telecommunications network. The term distinguishes a larger telecommunications facility from a local area network. The wide area network may be privately owned or leased, but the term usually connotes the inclusion of the public network. An intermediate form of network in geographical terms is a metropolitan area network. WAN is a regional or worldwide communications network in a geographic area, with a minimum distance typical of that between major metropolitan areas. Smaller networks include the metro and local area networks. A communications network provides common transmission and switching functions that allow the user to transport data between many sources and many destinations. Under ideal circumstances, the data arriving at its destination is identical to the data sent. The rate of arrival of bits at any point in the network is said to be the data rate at that point and is generally measured in bits per second. These bits can come from one source or multiple sources. The ability of a network to transmit at a given data rate is known as bandwidth. Figure 1: MESH connectivity of a WAN. A typical network is shown in the figure above. WANs commonly use MESH connectivity network. The characteristics of the transmission structure lead to an emphasis on the efficiency of the communication technique in the design of WANs. It is important to control traffic volume and avoid excessive delays. Since the topology of WANs is likely more complex than that of LANs, the routing algorithm also receives more emphasis. Many WANs also implement sophisticated monitoring procedures to keep track of which user uses the network resource. That's......half of the paper......any different person has the ability to use information from another computer. • Messages can be quickly sent to other people on the network. These messages have data, images, sounds or videos included in them called attachments. • Once set up, maintaining a network is a full-time job that requires hiring network supervisors and technicians. • Available to hackers or other external threats ConclusionWide Area Network is a collection of computers and network resources connected via a network over a geographic area. WANs are commonly connected via the Internet or through special agreements with telephone companies or other service providers. A WAN is different from a MAN because of the distance between each network. In a WAN, a network can be anywhere from several hundred kilometers to the other side of the world in a different country.