Solution:

An electric razor and an electric trimmer are essentially the same devices by build.

But the major difference between the both comes in terms of their usage and the blades that they come with.

Electric razors are made for specifically for providing a clean shave. It has lesser battery power but more aggression towards clipping hair.

Electric Trimmers on the other hand are not meant for clean shaves.

They come with special combs fixed onto them that aid in proper grooming and trimming of the beard stubs to desired shapes and sizes.