An auxiliary send and return does not stop the signal like an insert, but simply sends a portion of the signal to the processor (auxiliary send). The processed signal is then returned to the main mix (through an auxiliary return) blending the processed (dry) signal from the track with the unprocessed (wet) signal from the processor. Auxiliary sends and returns are commonly used with reverbs, delays, and some time-based effects because each of these processors requires both wet and dry signals to be mixed together.
Auxiliary Send and Return
-