Hi,
often there are four motors.
if you spin the back motor faster than the front motor it moves forward.
(indeed forward and backward is relative with such a symmetirc vehicle...)
two motors spin cw, two motors spin ccw.
If ccw are spinning faster than the cw, then the drone rotates cw (and vice versa)
If all motors run faster then the drone goes up, if all motors spin slower then the drone goes down.
All movements are just a question of the four motor´s spin rates.
Klaus