Computer Network

• Two or more devices connected together to share resources.

  Computer Network
• It is a telecommunications network that allows computers to exchange data.

  Computer Network
• The physical connection between networked computing devices is established using either cable media or wireless media (radio waves/infrared).
• A private network within an organization that resembles the internet.

  Intranet
• Organizations use this to provide information to their employees.

  Intranet
• Typical applications include electronic telephone directories, email addresses, employee information, internal job openings and much more.

  Intranet
• A private network that connects more than one organizations.

  Extranet
• Many organizations use the internet technologies to allow suppliers, customers and business partner limited access to their network. 


  Extranet
• The purpose is to increase efficiency and reduce costs.

  Extranet
• A public network.

  Internet
• Worldwide collection of networks that links million of business, government agencies, educational institution and individuals.

  Internet
• Its users can access service like web browsing, email, file transfer, mailing list, chat rooms, instant messaging and newsgroups.

  Internet
• PANs

  Personal Area Networks
• LANs

  Local Area Networks
• MANs

  Metropolitan Area Networks
• WANs

  Wide Area Network
• Is a computer network used for communication among computer and different information technological devices close to one person. (10 meters)

  PANs
• It is a small network established for communication between different devices such as laptops, computers, mobiles, etc. It may include wired and wireless devices.

  PANs
• A network that connects computers and devices in a limited geographical area such as a home, school, office building, or closely positioned group of buildings.

  LANs
• Each computer or device on the network is called a _.

  Node
• Wired LANs are most likely based on Ethernet technology.
• High speed network that connects local area network in Metropolitan Area such as city or town and handles bulk of communication activity across the region.

  MANs
• Typically includes one or more LAN but covers a smaller geographically area than a WAN.

  MANs
• A computer network that covers a large geographic area such as a city, country, or even intercontinental distances.

  WANs
• Uses a communications channel that combines many types of media such as telephone lines, cables, and air waves.

  WANs
• Often makes use of transmission facilities provided by common carriers, such as telephone companies.

  WANs
• One of the most prominent examples of the existing WANS is the Internet.
• The architecture of a network is a logical design that determines how the devices in the network communicate.
• The devices communicate to other devices through a central computer referred to as a server.


  Client Server Architecture
• A terminal with high processing power, which provides services for the other computers on the network.

  Server
• A terminal that accesses the resources available on a server.

  Client
• No specific distinction exists between a client and a server.

  Peer to Peer Architecture
• Any node can provide a service as well as send a request for a service from another node on the network. It allows sharing of resources, data, and users. Each node on the network has full control over the network resources.

  Peer to Peer Architecture
• A composition of two different types of elements.

  Hybrid Architecture
• Created to get the benefits of both, the peer-to-peer and the client-server architectures in a network.


  Hybrid Architecture
• The pattern of interconnection of nodes in a network.

  Network Topology
• This layout also determines the manner in which information is exchanged within the network.

  Network Topology
• Terminators at both end of BUS absorb signal, removing it from BUS.


  Bus Topology
• Normally coaxial cable is used.


  Bus Topology
• Popular topology for data network.

  Bus Topology