Understanding the audio term"Buss or Bus":

When you look at a mixer or audio rack, you will see wires connected to an input or output. These connections from input to output are carrying signals. This passing of signals is called a "buss or bus". You will often see such words used in audio software also, when referring to either grouping signals or audio connections. The term describes where the signal is going, such as bus 2 or bus 3 etc.