What is the difference between an inner tail light assembly and an outer tail light assembly?

Question

I'm trying to replace a passenger side tail light assembly (well, actually only the red plastic is broken, but that doesn't seem to come separately) for a 2015 Impala, and I see parts sites listing right/inner and right/outer as two separate things. What do they mean?

Answer 1

The tail lights on this car look like:

(image source)

The outer assembly is the one on the quarter panel:

The inner assembly is the one on the trunk:

I'm 99% sure of this, but note that it is the result of a bunch of Google searching, and generic product pictures on parts sites make finding a clear image confusing.

If somebody could confirm this that'd be great. You could also call the dealer's parts department and ask.