which is also called microprocessor or processor – is in charge of processing data. How it will process data will depend on the program. The program can be a spreadsheet, a word processor or a game: for the CPU it makes no difference, since it doesn’t understand what the program is actually doing. It just follows the orders (called commands or instructions) contained inside the program. These orders could be to add two numbers or to send a piece of data to the video card, for example.