What does the system bus connect in a computer?

The system bus is a crucial component in a computer architecture, serving as the primary communication pathway that connects the CPU to system memory, often referred to as RAM. It facilitates the transfer of data and instructions between the CPU and memory, enabling the processor to read information from and write information to the memory. This connection is essential for the efficient functioning of the computer, as the CPU relies on the memory to store the data currently being processed and to fetch instructions necessary for operation.

The system bus typically comprises three main functions: the data bus, which carries the actual data; the address bus, which sends the addresses of where the data needs to go; and the control bus, which manages the timing and control signals for data transfers. This comprehensive connectivity allows for instantaneous data exchanges vital for software applications and for overall system performance.

In contrast, while the connection between the CPU and external devices is indeed facilitated by other buses (like the I/O bus), and connections exist between memory and storage drives as well as the motherboard and power supply, the system bus specifically denotes the critical link between the CPU and memory, which is paramount for processing tasks.