Computer hardware includes physical components like the system unit, monitor, keyboard and mouse. The document defines and describes these common computer components and others like the computer mouse, keyboard, monitor, system unit, power supply unit, optical disk drive, floppy disk drive, hard disk drive, integrated drive electronics, random access memory, central processing unit, expansion cards, video cards, connectors, and parts of the motherboard such as the CPU socket, memory slots, SATA slots, read-only memory, CPU fan and heat sink, CMOS, BIOS, northbridge, southbridge, PCI slot, AGP slot, ATX power connector, primary/secondary connectors, floppy disk drive connector, super I/