A motherboard is the primary circuit board in a desktop or laptop computer that connects and allows communication between all the essential components. It serves as the central hub for the entire system, linking the CPU (Central Processing Unit), RAM (Random Access Memory), storage devices, power supply, GPU (Graphics Processing Unit), and various other peripherals.

The motherboard features a CPU socket where the processor is installed, along with DIMM slots for RAM installation. It also includes expansion slots, such as PCIe (Peripheral Component Interconnect Express) for adding expansion cards like graphics cards, sound cards, and network cards.

Integrated circuits (ICs) on the motherboard manage the flow of data between components. The chipset (often divided into northbridge and southbridge) controls communication between the CPU, memory, and other peripherals, determining the overall system performance and compatibility.

Additionally, motherboards provide connectivity options like USB ports, audio jacks, Ethernet ports, and sometimes Wi-Fi. They also have SATA or NVMe connectors for storage drives, and power connectors to link with the power supply unit (PSU).

Motherboards come in different form factors, such as ATX, Micro-ATX, and Mini-ITX, determining the size of the case and the number of expansion slots and ports available. A quality motherboard ensures stability, upgradability, and the longevity of a computer system.