A typical personal computer consists of a case or chassis in a tower shape (desktop) and the following parts:
Motherboard:
- Motherboard - the "body" or mainframe of the computer, through which all other components interface.
- Central processing unit (CPU) - Performs most of the calculations which enable a computer to function, sometimes referred to as the "brain" of the computer.
- Computer fan - Used to lower the temperature of the computer; a fan is almost always attached to the CPU, and the computer case will generally have several fans to maintain a constant airflow. Liquid cooling can also be used to cool a computer, though it focuses more on individual parts rather than the overall temperature inside the chassis.
- Random Access Memory (RAM) - Fast-access memory that is cleared when the computer is powered-down. RAM attaches directly to the motherboard, and is used to store programs that are currently running.
- Firmware is loaded from the Read only memory ROM run from the Basic Input-Output System (BIOS) or in newer systems Extensible Firmware Interface (EFI) compliant
- Internal Buses - Connections to various internal components.
- PCI
- PCI-E
- USB
- HyperTransport
- CSI (expected in 2008)
- AGP (being phased out)
- VLB (outdated)
- External Bus Controllers - used to connect to external peripherals, such as printers and input devices. These ports may also be based upon expansion cards, attached to the internal buses.
- parallel port (outdated)
- serial port (outdated)
- USB
- firewire
- SCSI (On Servers and older machines)
- PS/2 (For mice and keyboards, being phased out and replaced by USB.)
- ISA (outdated)
- EISA (outdated)
- MCA (outdated)