Effects on Aux Track versus Duplicate Audio Track

[JesseF]

Hi,

Is there a difference between putting a software insert on an Aux track with an audio track's signal being bussed to it, versus duplicating the audio track and putting the insert on that?

To me it seems like there wouldn't be, and that duplcaiting the audio would actually be a waste of a track

Also, my friend who goes to school for this stuff says they call effecting the duplicate track "dual processing" Anyone heard that term being used in this context?

Thanks