Catchment vs watershed

Discussion created by malnunn on Feb 11, 2014
Latest reply on Jul 20, 2015 by MBoucher21
Forgive me if this is a blatantly obvious question, but what exactly is the defined difference between a catchment and a watershed? I've always come across the terms as fairly synonymous. However now I've been working my way through the Arc Hydro tutorial and find that having delineated catchments and adjoint catchments as part of the terrain pre-processing workflow that there is now a specific process for watershed delineation.

Wouldn't a watershed be the sum of the local and upstream catchments for a given point, while a subwatershed would be the local catchment?