Personal Computer Hardware

Motherboard

The motherboard is the main component inside the case. It is a large rectangular board with integrated circuitry that connects the other parts of the computer including the CPU, the RAM, the disk drives (CD, DVD, hard disk, or any others) as well as any peripherals connected via the ports or the expansion slots.

Components directly attached to the motherboard include:

The CPU (Central Processing Unit) performs most of the calculations which enable a computer to function, and is sometimes referred to as the "brain" of the computer. It is usually cooled by a heat sink and fan. Most newer CPUs include an on-die Graphics Processing Unit (GPU).
The Chipset, which includes the north bridge, mediates communication between the CPU and the other components of the system, including main memory.
The Random-Access Memory (RAM) stores the code and data that are being actively accessed by the CPU.
The Read-Only Memory (ROM) stores the BIOS that runs when the computer is powered on or otherwise begins execution, a process known as Bootstrapping, or "booting" or "booting up". The BIOS (Basic Input Output System) includes boot firmware and power management firmware. Newer motherboards use Unified Extensible Firmware Interface (UEFI) instead of BIOS.
Buses connect the CPU to various internal components and to expansion cards for graphics and sound.
- Current
  - PCI Express: for expansion cards such as graphics, sound, network interfaces, TV tuners, etc.
  - PCI: for other expansion cards.
  - SATA: for disk drives.
- Obsolete
  - AGP: superseded by PCI Express.
  - ATA
  - VLB: VESA Local Bus, superseded by AGP.
  - EISA
  - Micro Channel architecture
  - ISA: expansion card slot format obsolete in PCs, but still used in industrial computers.
Ports for external peripherals. These ports may be controlled directly by the south bridge I/O controller or provided by expansion cards attached to the motherboard.
- USB
- Memory Card
- FireWire
- eSATA
- SCSI