The motherboard is the main circuit board inside a computer case. It provides the physical sockets, slots, and electrical pathways that hold and connect the processor, memory (RAM), storage drives, expansion cards, and ports for peripherals such as the keyboard, mouse, and monitor.
Because every one of these components plugs into the motherboard, it is the motherboard that allows them to communicate with one another and share power and data along its circuitry. Storing data, performing calculations, and providing internet access are each carried out by specific components mounted on the motherboard, such as storage drives, the central processing unit, and a network card or modem, but none of those tasks is the motherboard's own function; the motherboard's role is to physically and electrically connect all of these components into a single working system.
Examination reminder: when a question asks what "connects" or "houses" the other hardware components together, the expected answer is the motherboard, since it is the platform the rest of the hardware is built on rather than a component that performs a task on its own.