A motherboard is the main circuit board of a computer that connects and allows communication between various hardware components. It houses the CPU, RAM, and other critical components, and provides connectors for additional peripherals like storage devices, graphics cards, and expansion cards. The motherboard also contains the chipset, which manages data flow between the processor, memory, and peripherals. Its importance lies in its role as the central hub that integrates and facilitates the interaction of all essential components, ensuring that the computer operates effectively and efficiently.