The document discusses the main components of a computer system unit:
The motherboard holds important components and connects other components. The BIOS software initializes devices and loads the operating system at startup. RAM temporarily stores the operating system, applications, and data for quick processor access while powered on. The hard drive permanently stores data, files, and the operating system. The graphics card outputs images to displays. The sound/audio card handles audio input/output. The CPU processor carries out program instructions to process data. The network card physically connects the computer to a local area network.