Chapter 19: Networks

Chapter 19: Networks

1. Network

   • when 2 or more computers are connected together to exchange data
     • each computer must have a network interface and a network communications software

2. LAN: Local Area Network

   • for computers in the same building
     • e.g. in homes, offices and schools
   • connects the computers wirelessly or using cables

3. WAN: Wide Area Network

   • for computers connected over a wide geographic area
     • e.g. a business that has offices in multiple countries
   • connects the computers using telephone networks and satellites

4. Internet

   • Internet is a network of computers across the world
   • uses telephone lines and satellite to communicate
   • allows data and resources to be shared
   • activities such as messaging, shopping, banking, advertising etc. can take place online

5. Intranet

   • Intranet is a network providing similar services to the internet
   • generally limited to one organisation
     • e.g. a school or company
   • there are restrictions to who can use it and what they can use on it

6. Extranet

   • Extranet is a part of the intranet that is able to be accessed by authorised members of the public using the internet

7. Network Components

   • Bridge
     • connects two networks of the same type
       • e.g. a LAN and a LAN
   • Gateway
     • a system that allows a LAN to connect to a WAN
       • e.g. the internet
   • Switch
     • a device that filters data packets and forwards packers between segments of a network
   • Router
     • a device that...
       • forwards data packets along a network
       • is generally located at gateways
       • determines the best path for forwarding the packets

8. Packet Switching