You may have heard the terms "shower pan" and "shower base" used interchangeably, but they are actually two different things. A shower pan is a single-piece unit that is installed directly on the subfloor and slopes towards the drain. A shower base, on the other hand, is a multi-piece unit that is typically installed on top of a bed of mortar or a foam shower base. Shower bases are available in a wider variety of sizes and shapes than shower pans.
Main points:
Shower pans are single-piece units installed directly on the subfloor.
Shower bases are multi-piece units installed on top of a bed of mortar or foam.
Shower bases are available in a wider variety of sizes and shapes than shower pans.