Computers can be classified in three main ways: by purpose, type of data handled, and size/capacity/speed. By purpose, they are general-purpose computers for varied applications or special-purpose computers for specific tasks. By data type, they are analog for continuous data, digital for discrete data, or hybrid for both. By size, they range from supercomputers for scientific use, to mainframes for large organizations, midrange servers for hundreds of users, and microcomputers/personal computers for individuals.