The term for a shared communications medium, derived from the common usage of the term in computer architecture jargon. Busses have many publishers and subscribers to information, and may have various synchronization policies depending on the purpose and economics.

Busses usually consist of a system of channels which are linked by a common behavior or software, but those channels may or may not be significant to the overall abstraction (in terms of, say, reliability). Unlike channels, busses are usually software emulations; even what is thought of as a hardware bus is a system of hardware mediated by some processor.