Computer is an electronic device capable of accepting, storing and processing data to make it useful information. There are several types of computers including analog, hybrid, mainframe, microcomputer, desktop, laptops, personal data assistants, minicomputers, supercomputers, and wearable computers. Each type has distinct characteristics such as analog computers using continuous variables for mathematical operations, hybrid computers combining digital and analog segments, mainframes being used by large organizations for critical applications, and supercomputers effectively performing highly calculation-intensive tasks.