Motherboards are the main circuit boards in computer cases and serve as the point of connection for most other computer components and peripheral devices. In tower computers, the motherboard is located on either the left or right side of the case and is usually the biggest circuit board inside. It houses the central processing unit (CPU) and random access memory (RAM), and it has expansion slots and ports that connect to external hardware, like video cards, hard drives, optical drives, and USB ports.
The motherboard distributes electricity to different parts of the computer and facilitates communication between them, as well. It has a power connector plug that receives electrical energy from the computer case and converts it into a format that all of the hardware components can use. It also has circuits that ensure that the power is distributed optimally to different components and reduces overall computer energy consumption.
Computer components communicate with each other over connections on the motherboard called buses. These circuits encode information in a language that the different hardware can understand, so that when one component sends a signal over a bus, it instantly reaches all of the other hardware connected to it.
Modern motherboards include ports that can be used to connect external devices, like printers and scanners, as well as USB ports. They may also have ports that connect to a power supply unit and case electronics, and they will typically have slots for connecting the CPU, RAM sticks, and expansion cards. The motherboard will also have ports for connecting to the monitor, keyboard, and mouse, as well as a port that allows a floppy drive to be attached to the computer.