You might find these pages interesting: https://en.wikipedia.org/wiki/S-100_bus https://en.wikipedia.org/wiki/S-100_bus https://en.wikipedia.org/wiki/Bus_(com

You might find these pages interesting: https://en.wikipedia.org/wiki/S-100_bus https://en.wikipedia.org/wiki/S-100_bus https://en.wikipedia.org/wiki/Bus_(computing) https://en.wikipedia.org/wiki/Bus_(computing) It’s a physical data highway that allows devices to communicate with each other. Early routers were ‘normal’ computers with lots of network cards plugged into a bus. Data arrived on one card, and was routed to another by the operating system. Your home router is still a computer, but miniaturises everything to a much simpler circuit board with the network connectors directly soldered on.