NETWORK
 NETWORK ARCHITECTURE
 NETWORK TOPOLOGY

  Network Basic Definition:
 A network is a collection of computers and mobile devices connected together via communications devices and transmission media, often wirelessly allowing computers to share resources

Communication Device:
Hardware component that enables a computer to send (transmit) and receive data, instructions and information to and from one or more computer
  • Modem: a device that enables a computer to communicate over analog networking media such as connecting the Internet via telephone lines
  • Wireless Access Point: a device on a network that connects wireless device to that network
  • Router: a device that connects multiple networks together
  • Hub: a device that provides a common central connection point for nodes on network
  • Switch: a device that used to connect multiple devices on a single ( typically wired) network
  • Network Interface Card: an adapter/expansion card that connect a computer to a network

Transmission Media:
the material or substances capable of carrying one or more signals
  • Physical: send signals through cable, wire or tangible materials
    • Twisted-pair cable: physical transmission media which the cable consisting of pairs of copper wire that are twisted together
    • Coaxial cable: consists of a single copper wire surrounded by at least three layers
    • Fiber optic: consists of dozens or hundreds of thin strands if glass or plastics that use light to transmit signal
  • Wireless: sends signals through the air or space
    • Infrared: sends signals through infrared light waves from one device to another
    • Microwaves: radio waves that rovides a high-speed signal transmission using electromagnetic radio wave
    • Cellular radio: form of roadcast radio that is in wide use for mobile communication
    • Broadcast radio: distributed radio signal through the air over long distance and short distance
    • Commucnication satellite: an earth-orbiting device that relays communications signals over long distances
    • Bluetooth: a networking standard for every short-range wireless connections; the devices are automatically connected once they get within the allowable range
   
Advantage of network
 Disadvantage of network
Hardware Sharing- Network facilitate the sharing hardware devices such as printer
 Undesirable Sharing - Viruses are easily spread over network and the Internet
Data and Information Sharing - enable many people to access and share same data such as database and group software development
 Security issue - a computer hacker can get unauthorized access by using different tools
Facilitate communication - people communicate efficiently and easily via e-mail
 Network hardware, software and setup costs - setting up a network requires an investment in hardware, software of network
Internet access sharing - small computer networks allow multiple users to share a single Internet connection.
 Illegal or undesirable behaviour - typical problem include the abuse of company resources, distraction that reduce productivity, the downloading of illegal or illicit material and even software piracy (abuse company production)