Basically, more gear multiplies torque less multiplies it less. For example, my car has a 3.23 rear gear so the output torque is 3.23 times more than the input torque. Think of shorter gears like a longer lever. If you put a big cheater pipe on the end of a socket handle, you get more mechanical advantage but need to move the end of the handle a farther distance than you would if the handle is shorter with less mechanical advantage. Thus, more distance is traveled at the input than at the output. Gears work the same way as they provide essentially an Archimedes Screw to move it a given distance straight up but traveling a longer overall distance. Basically, it's an inclined plane wrapped around a shaft. In this analogy, the pinion shaft is the screw and the ring gear is the vertical distance being traveled. You just take the vertical part and make a circle out of it, thus always climbing the same mountain.
