In the digital computer world there are currently different types of categories, which are based on price and performance. Two of these are:
Personal Computer (PC’s)A PC is a relative low-cost machine usually of desktop size (laptops, notebooks and palmtops are mush smaller).
Main FramesA mainframe is a large expensive machine with the capability of serving the needs of major business enterprises, government departments and scientific research establishments (the largest and fastest of these are called supercomputers).
Source/Further Reading: NOUN – http://www.nou.edu.ng/uploads/NOUN_OCL/pdf/SST/CIT%20101.pdf