Analog computer system is the very old computer system which operates on the mathematical variables in the form of continuously changeable physical quantities/entities like mechanical, electrical, hydraulic, etc. They use continuous values rather than discrete values so they work on analog signal.
Digital computers are the computer systems/machines which uses the binary number system, which has two digits: 0 and 1 and performs many computational tasks. It processes the data represented in discrete and the main three components of digital computers are input, processing and output.
