Computer: A computer is a device that computes or calculates numbers. A computer, however, does more than that. It can edit text, generate pictures or graphs, make animation, translate language and even play games or drive motorcars etc.
Computer System: A system is a set of components that works together to accomplish one or more common goals. A computer system can be said to be a system of three major components.
A. Computer Hardware: It includes all mechanical, electrical or electronic parts or components of the computer.
B. Computer Software: This includes operating system programmes or applications that instruct a computer how to process the data and generate required information.
C. Computer Personnel: People who prepare data for computerized input write computer programmes, monitor computer operations and distribute the output. There are also end users who use computer resources.