Thursday 9 August 2018

What are the Types of Computer Network?



PAN- Personal Area Network



1) A personal area network (PAN) is the interconnection of information technology devices within the range of an individual person, typically within a range of 10 meters.


 For example, a person traveling with a laptop, a Personal Digital Assistant (PDA), and a portable printer could interconnect them without having to plug anything in, using some form of wireless technology. Typically, this kind of personal area network could also be interconnected without wires to the Internet or other networks.

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  Also see wireless personal area network (WPAN) which is virtually a synonym since almost any personal area network would need to function wirelessly. Conceptually, the difference between a PAN and a wireless LAN is that the former tends to be centered around one person while the latter is a local area network (LAN) that is connected without wires and serving multiple users.


2) In another usage, a personal area network (PAN) is a technology that could enablewearable computer devices to communicate with other nearby computers and exchange digital information using the electrical conductivity of the human body as a data network. 

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  For example, two people each wearing business card-size transmitters and receivers conceivably could exchange information by shaking hands. The transference of data through intra-body contact, such as handshakes, is known as linkup. The human body's natural salinity makes it a good conductor of electricity. An electric field passes tiny currents, known as Pico amps, through the body when the two people shake hands. The handshake completes an electric circuit and each person's data, such as e-mail addresses and phone numbers, are transferred to the other person's laptop computer or a similar device. A person's clothing also could act as a mechanism for transferring this data.

LAN- Local Area Network



  A local area network (LAN) is a group of computers and associated devices that share a common communications line or wireless link to a server. Typically, a LAN encompasses computers and peripherals connected to a server within a distinct geographic area such as an office or a commercial establishment. Computers and other mobile devices use a LAN connection to share resources such as a printer or network storage.

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  Ethernet and WiFi are the two primary ways to enable LAN connections. Ethernet is a specification that enables computers to communicate with each other. WiFi uses radio waves to connect computers to the LAN. Other LAN technologies, including Token Ring, Fiber Distributed Data Interface and ARCNET, have lost favor as Ethernet and WiFi speeds have increased. The rise of virtualization has fueled the development of virtual LAN's, which allows network administrators to logically group network nodes and partition their networks without the need for major infrastructure changes.



  Typically, a suite of application programs can be kept on the LAN server. Users who need an application frequently can download it once and then run it from their local device. Users can order printing and other services as needed through applications run on the LAN server. A user can share files with others stored on the LAN server; read and write access is maintained by a network administrator. A LAN server may also be used as a web server if safeguards are taken to secure internal applications and data from outside access.



  In some situations, a wireless LAN, or WiFi, may be preferable to a wired LAN connection because of its flexibility and cost. Companies are assessing WLAN's as primary means of connectivity as the number of smartphones, tablets and other mobile devices proliferate.

MAN- Metropolitan Area Network


A metropolitan area network (MAN) is a network that interconnects users with computer resources in a geographic area or region larger than that covered by even a large local area network (LAN) but smaller than the area covered by a wide area network (WAN). 

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  The term is applied to the interconnection of networks in a city into a single larger network (which may then also offer efficient connection to a wide area network). It is also used to mean the interconnection of several local area networks by bridging them with backbone lines. The latter usage is also sometimes referred to as a campus network.Examples of metropolitan area networks of various sizes can be found in the metropolitan areas of London, England; Lodz, Poland; and Geneva, Switzerland. Large universities also sometimes use the term to describe their networks. A recent trend is the installation of wireless MAN's.

WAN- Wide Area Network


  A wide area network (WAN) is a geographically distributed private telecommunications network that interconnects multiple local area networks (LAN's). 

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  In an enterprise, a WAN may consist of connections to a company's headquarters, branch offices, colocation facilities, cloud services and other facilities. Typically, a router or other multi-function device is used to connect a LAN to a WAN. Enterprise WAN's allow users to share access to applications, services and other centrally located resources. This eliminates the need to install the same application server, firewall or other resource in multiple locations, for example.

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  A virtual private network (VPN) facilitates connectivity between WAN sites. An IPsec VPN is more commonly used in continuously open site-to-site connections, such as those between branch offices and headquarters locations. An SSL VPN is often the preferred choice for enabling remote access for individual users because the data transmitted from users across the WAN is encrypted. 


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Direct fiber optic links are also used to connect sites on a WAN – and they almost always offer greater performance, reliability and security than VPN's, but they are cost-prohibitive for most enterprises to procure and operate.





Source:
https://searchmobilecomputing.techtarget.com/definition/personal-area-network
https://searchnetworking.techtarget.com/definition/local-area-network-LAN
https://searchnetworking.techtarget.com/definition/metropolitan-area-network-MAN
https://searchenterprisewan.techtarget.com/definition/WAN



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