A computer is a programmable device that stores, retrieves, and processes data. The term "computer" was originally given to humans (human computers) who performed numerical calculations using mechanical calculators, such as the abacus and slide rule. The term was later given to mechanical devices as they began replacing human computers. Today's computers are electronic devices that accept data (input), process that data, produce output, and store (storage) the results (IPOS).
Computer overview
Below is a picture of a computer with each of the main components. You can see the desktop computer, flat-panel display, speakers, keyboard, and mouse in the picture below. We've also labeled each of the input devices and output devices.