1. an electronic device for storing and processing data, typically in binary form, according to instructions given to it in a variable program.
2. a peripheral device, as a keyboard or stylus, used to enter data into a computer for processing.
3. Output is defined as the act of producing something, the amount of something that is produced or the process in which something is delivered. An example of output is the electricity produced by a power plant. An example of output is producing 1,000 cases of a product.
4. A system unit is the part of a computer that houses the primary devices that perform operations and produce results for complex calculations. It includes the motherboard, CPU, RAM and other components, as well as the case in which these devices are housed.