Motherboard

It holds and allows communication between many of the crucial electronic components of a system, such as the central processing unit (CPU) and memory, and provides connectors for other peripherals.

Unlike a backplane, a motherboard usually contains significant sub-systems, such as the central processor, the chipset's input/output and memory controllers, interface connectors, and other components integrated for general use.

In very old designs, copper wires were the discrete connections between card connector pins, but printed circuit boards soon became the standard practice.

The central processing unit (CPU), memory, and peripherals were housed on individually printed circuit boards, which were plugged into the backplane.

The most popular computers of the 1980s such as the Apple II and IBM PC had published schematic diagrams and other documentation which permitted rapid reverse engineering and third-party replacement motherboards.

Usually intended for building new computers compatible with the exemplars, many motherboards offered additional performance or other features and were used to upgrade the manufacturer's original equipment.

Business PCs, workstations, and servers were more likely to need expansion cards, either for more robust functions, or for higher speeds; those systems often had fewer embedded components.

This even included motherboards with no upgradeable components, a trend that would continue as smaller systems were introduced after the turn of the century (like the tablet computer and the netbook).

Early personal computers such as the Apple II and IBM PC include only this minimal peripheral support on the motherboard.

Occasionally video interface hardware was also integrated into the motherboard; for example, on the Apple II and rarely on IBM-compatible computers such as the IBM PCjr.

Motherboards are produced in a variety of sizes and shapes called form factors, some of which are specific to individual computer manufacturers.

CPU sockets on the motherboard can most often be found in most desktop and server computers (laptops typically use surface mount CPUs), particularly those based on the Intel x86 architecture.

By combining many functions on one PCB, the physical size and total cost of the system may be reduced; highly integrated motherboards are thus especially popular in small form factor and budget computers.

This typically requires the use of a low-power CPU, as well as a careful layout of the motherboard and other components to allow for heat sink placement.

A 2003 study found that some spurious computer crashes and general reliability issues, ranging from screen image distortions to I/O read/write errors, can be attributed not to software or peripheral hardware but to aging capacitors on PC motherboards.

In desktop PCs and notebook computers, the motherboard cooling and monitoring solutions are usually based on a super I/O chip or an embedded controller.

UEFI is a successor to BIOS that became popular after Microsoft began requiring it for a system to be certified to run Windows 8.