What is the Internet?

The Internet was developed to allow computers to communicate with each other. They do so by sending packets that consist of 0s and 1s. The packet includes the source and destination.

  • Computer system: Devices that are used for a similar purpose
  • Computer network: Computers that are connected to each other in order to communicate
  • Packet switching: The message that the computer sends is broken into many packets. These can be sent in a random order and are put in the original order once they arrive at the destination device.
  • Path: The journey (I couldn’t think up of a better word) of a packet from source to destination
  • Routing: Routers determine the best path to send a packet from source to destination
  • Bandwidth: The amount of data that can be sent in a network Units include bits per second


A protocol is the rules that determine how a packet is sent from source to destination.

There are many protocol models, such as OSI, and TCP/IP.


TCP/IP model layers:

  • Application: Includes web servers and DNS DNS translates an IP address to a web URL that is easy for us to remember Protocols: HTTP, HTTPS
  • Transport: Protocols: TCP, UDP TCP: Slow, but reliable UDP: Fast, but unreliable
  • Internet: Consists of source and destination IP address, used for transportation of data The internet is scalable, it includes LANs and WANs
  • Network access: Deals with the hardware, associated with getting the information from binary Protocols: Ethernet NICs (Network interface cards) use the network access protocol and contain a MAC address (used to identify hardware)