An example of a motherboard is the main board in your computer that contains the circuitry for everything required for you to type the words on your keyboard.
motherboard - Computer Definition
Also called the "system board," "main board" "base board" or "logic board," it is the primary printed circuit board in a computer or other electronic device. In a modern desktop computer, the motherboard contains the CPU and memory sockets as well as the chipset, which houses the control circuits for all the peripheral devices. It also has a PCI-Express slot for a high-end graphics card and PCI slots for additional peripherals. Laptop motherboards have no expansion slots for more peripherals. Want to Sound Like a Cool Geek? Every now and then, say "mobo" instead of motherboard. See CPU, chipset, PCI Express, PCI and controller.