Internet - U5

• Computer Network

  A computer network is a set of two or more computers connected together for the purpose of sharing resources.
• Network Components

  1.Network Interface Card (NIC)

  2.Internet Service Provider (ISP)

  3.WiFi

  4.Modem

  5.Router

  6.Firewall
• Network Interface Card (ISP)

  • NIC is a component that takes information from the computer and sends it out onto the network.
  • It may be integrated into the computer's motherboard or may be a separate card.
• Internet Service Provider (ISP)

  An ISP is a company that provides access to the Internet
• WiFi

  • Most popular wireless networking technology that allows devices(e.g; computers, mobile devices, and other equipment) to interface with the Internet
  • It uses radio waves to provides wireless high-speed Internet.
• Modem


  A modem is a hardware that allows a computer to send and receive data over a communication link or cable.
• Router

  A router is a hardware that allows two or more networks to be connected.

  To access to the internet, the router must be connected to a modem.

  Nowadays, modem/router unit performs both these functions in one device.
• Firewall

  A firewall is a software or a hardware that prevents unauthorised access to or from a private network by monitoring and controlling all incoming and outgoing network traffic.
• Router allows communication between your local home network and the Internet
• Types of Networks

  PAN - Personal Area Network

  LAN - Local Area Network

  MAN - Metropolitan Area Network

  WAN - Wide Area Network

  SAN - Storage Area Network

  VPN - Virtual Private Network
• Personal Area Network - PAN

  It is a connection of devices for an individual person within a small office or room.
• Network Components - PAN

  Wireless PAN is most commonly achieved by using Bluetooth.

  Wired PAN is mostly done by using USB ports.
• Local Area Network - LAN

  It is a geographically small computer network.
• LAN can be a single room, building or group of buildings shared by many users. Example: A school network
• Network Components for LAN

  1. Network Interface Card

  • The NIC can support both wireless and wired networks.

  2. Interconnection

  • Connections can be done using cables or Wireless Access Point (WAP)
  • Network cables are the wires which carry the information between the different computers in a wired LAN.
  • For WAP, antennas are used to send radio waves to computers which are found in wireless LAN.
• Metropolitan Area Network - MAN

  It is a network designed for a larger geographical area such as a town or city.
• What is the purpose of MAN?

  To connect LANs together.
• Network Components of MAN

  Same as in LANs and WANs.
• Wide Area Network - WAN

  It is a network that spans over a very large geographical area. It can connect computers across the country or around the world.
• Network Components for WAN

  1. Interconnection

  • It can be done by using cables or Wireless Access Points.

  2. Server

  
  

  3. An Internet Connection

  • It can be via a modem or via a router.

  4. Firewall

  To block any unauthorized access.
• Server

  It is a powerful computer which organizes and manages the communication around the network. It also controls access to the files which are stored in a central location.
• Storage Area Network - SAN

  It is a network of storage devices accessible to multiple servers. It can span over a large geographical area and is useful for companies with many branches.
• Network Components for SAN

  1. Servers
  2. Cables
  3. Storage devices