Unit 3- Computer Science

• Definition of a Wide Area Network (WAN):

  • Any network in which computers communicate using resources supplied by a 'third party carrier' like BT
  • Uses cables, telephone lines, satellites, or radio waves to connect two or more remote locations
  • The Internet is the largest WAN in the world
• The Internet is a worldwide collection of computer networks

  • It is a collection of inter-connected networks
  • Services like the web, voice over IP (VoIP), email, and file sharing make use of the Internet
  • The World Wide Web is one service that utilizes the Internet
• Importance of IP addressing and DNS services on the Internet:

  • Every computer in the world has an IP address for communication
  • IP addresses are essential for identifying resources on the Internet
  • DNS services translate domain names into IP addresses for easier access
• Need for Network Interface Cards (NIC) and MAC addressing:

  • NIC is built into every networked device for communication
  • MAC addresses are unique identifiers assigned to NICs by manufacturers
  • MAC addresses help in routing data packets to the correct destination
• Explanation of packet switching:

  • Data is broken into packets for efficient transmission
  • Each packet contains header information like IP addresses, sequence numbers, and error checking data
  • Packets flow through the Internet via different routes and are reassembled at the destination