Introduction to computer networks


What are computer networks?


Computer networks are two or more computers, or hardware devices, connected in such a manner as to be able to communicate in some form or share resources. Large networks can be comprised of several smaller networks connected in some fashion. There are many different types of networks depending on the characteristics of each particular network. One of the most famous of all networks is the internet.

The main reason for computer networks is the ability to share data between computers. This data needs to be split up into more manageable chunks that can be passed along the network to their destination. The chunks of data are known as packets, the data packets are sent along a series of connected devices until they reach their final destination where they are cleverly put back together into the original form of whatever was sent. The complex rules / procedures deciding what routes the data packets take and how these packets are handled at both ends are called protocols.


A brief history of networks


ARPANET is one of the earliest examples of a computer network with its development starting in 1966. Then, through a series of developments and breakthroughs, networks develop overtime into what we think of today. For example: the first email was sent by Roy Tomlinson in 1971, Ethernet was developed 1973, the TCP/IP protocol was developed in 1981, and details on firewall technology were first published in 1988.


Advantages and disadvantages of computer networks


  • Save money by sharing printers and other such devices.
  • Multi-user / enterprise software licenses often work out much cheaper in the long run than buying lots of individual software licenses for each machine.
  • Files can easily be shared between machines or accessed by multiple machines in a single location.
  • Security can be managed from a single server.
  • Data can be backed up by a single machine to a single backup location.



  • Initial costs of infrastructure and configuration / setup can be very expensive.
  • Managing the network can be a complex job and will often require highly trained technicians / engineers.
  • If the file server fails everybody‚Äôs access to it, and all the files on it, is prevented. This can be prevented with server redundancy and replication but this can increase cost and complexity of the network.
  • Malware can traverse a network, potentially spreading to other machines.


For a more in-depth introduction to computer networks see this crash course intro below:



Computer networks are largely about communication. Now that you have a better understanding of what networks are why not move on to our section on communication basics.