Device on a computer's motherboard that provides a data path between the CPU and attached devices (keyboard, mouse, disk drives, video cards, etc.).
Like a vehicular bus that stops at designated stations to pick up or drop off riders, a computer bus receives a data signal from the CPU and drops it off at the appropriate device (for example, the contents of a file in RAM are sent, via the bus, to a disk drive to be stored permanently). Conversely, data signals from devices are sent back to the CPU. On a network, a bus provides the data path between the various computers and devices. See also USB .