CertiGuide to A+ (Core Hardware)  9  Chapter 0001:  Power Supplies - System Board

IX  POST 1 Frontside / Backside Bus

While the term bus has a slightly different meaning in a PC than it does on a roadway, the concept is identical. A Greyhound bus leaving Seattle and heading to Los Angeles makes stops in towns along the way to pick up or drop off passengers.

Inside a PC (or even a network of computers) the bus is a transmission path that drops off or picks up signals (instead of people) from every device (instead of town) attached to the line.

If you were on the bus from Seattle to Los Angeles, you would still stop at Olympia, Washington. Since Olympia was not your destination, you ignored it. In the same fashion, devices only pay attention to signals addressed to them. If the signal is not addressed to the device, it is ignored the same way you disregarded the stop in Olympia.

Just as Greyhound has more than one route, the PC has more than one bus. One area that had been receiving a great deal of attention is the Frontside Bus.

IX  POST 1 Frontside / Backside Bus