FCOM and AFM are different names for the same thing. I believe FCOM is the current preferred term.
Must depend on where you fly. We do carry both the AFM and an FCOM (or on the Boeing an OM B II). The FCOM contains information that is in the AFM, but not all, and much more user friendly than the AFM. Of course, as always, both manuals are only available electronically, as has been the case for the last 15 years.