I had both
The "Half bath" (restroom) was a Sea Land type Gravity. Step on the pedal and gravity did it's thing
The "Full bath" (included a phone booth shower) had a Macerator or Vac-u-flush type. Push the button and it fills up some more then WOSH it's pumped to the tank amidships and then it fills up the rest of the way.
Dead batteries=no flush
There are supposed to be sensors to tell when the tank was full.. Never installed.
That was fun.