The picure above shows 24 digits (6 x 4 digit modules). The display modules each contain a 4 x 7 segment Common Cathode display, a DIL resisor pack on the modules right-hand side, and there are 4 n-channel SMT MOSFETS underneath.
The advantage of using modules on breadboards is the vast amount of time, and wire that's saved. You can throw a quick circuit together in no-time if you already have the modules pre-built. It also saves a lot of breadboard space.