A computer is a device that accepts information (in the form of digital ized data) and manipulates it for some result based on a program or sequence of instructions on how the data is to be processed.
Complex computers also include the means for storing data (including the program, which is also a form of data) for some necessary duration. A program may be invariable and built into the computer (and called logic circuitry as it is on microprocessors) or different programs may be provided to the computer (loaded into its storage and then started by an administrator or user). Todays computers have both kinds of.