An insert basically inserts the processor or effect in the flow of the signal chain. It does this by stopping the audio in its path, routing it to the processor, processing the signal, returning it back to its path immediately after it was stopped, and then continuing on as a completely processed signal. At this point the entire signal has been processed (wet) and there is no unprocessed (dry) signal left in the track. This is how an EQ works on a mixing console and how a DAW ‘inserts’ a plug-in on a track. Once you make changes to the inserted EQ or compressor (or whatever the processor might be), the signal from that point on in it’s flow is processed.
