A computer system is the "complete" computer. This means that it is made up of a CPU, memory and related electronics. This can be used for many different things, such as personal computers, credit card scanners or airplane computers.

Computer systems are important in the modern world, as they can remove human error for many situations, and help or guide us in many different everyday tasks.

There are many different factors to consider when developing a computer system. These include ethical, environmental and legal concerns. Ethical concerns cover whether what the computer is doing is right or not (such as hacking people or stealing money). Environmental concerns cover whether what the computer is doing is right for the environment (such as deforestation). Legal concerns cover anything that may inhibit the computer because of the law (copyright infringements).

Computer systems need to be reliable because, if one breaks at a critical point, it could seriously hurt or kill someone, or lose research they had been investigating, among many other things. Examples of reliability being needed are found in planes (autpilot), GPSs, personal computers and many more.

Computer systems need to be maintained, used and developed to professional standards. This is because, if any of these aren't done, it could lead to errors or malfunctions within the computer system. For example, if the dust isn't cleaned out of a personal computer regularly, the fans could become clogged and stop cooling the computer as effectively.