The document describes the main parts of a computer system including the system unit, mouse, keyboard, monitor, printer, speakers, web cam, and scanner. The system unit contains electronic components like the CPU that process information. The mouse is used to select items on screen and is connected to the system unit by a wire. The keyboard has keys for typing letters, numbers, and special functions. The monitor displays visual information like text and graphics. The printer transfers data from the computer onto paper. Speakers play sound, and may be built into the system unit or connected with cables. A web cam can capture images and transmit them across the internet. The scanner copies pictures and documents for computer projects.