Components of a computer need to communicate values between themselves. Registers must send binary numbers to the adder. Decoders must get the address to be decoded. Memory must both send and receive data. And control signals of various types, issued by the control circuitry whose heart is either a microcode engine or a hardware DFA, flow around the system. Values move around on pathways called buses.

A bus is nothing more than a group of wires that send logical values (1s and 0s) between computer components. Each separate wire in a bus has its own meaning.

The word bus comes from the Latin adjective omnibus, meaning all or everyone. Like their diesel-guzzling counterparts on the streets, computer buses carry all the data from one place to another.