Lemme Spline this to you, Lucy.
So, in a transaxle, there is an input shaft with splines that the clutch disk rides on out in the bellhousing.
On the inner-end of the input shaft are some speed range gears machined from or splined to the shaft and a synchronizer hub or two splined to the shaft with a gear on either side of the synchronizer hub that are riding on bushings or bearings over the shaft (they only transmit power when the synchro hub outer sleeve slides over and mates with them (I thought this was a fambilly site!)
Then there is an intermediate shaft (some folks call them output shafts - they are wrong, but watcha gonna do?), with some gears machined from or splined directly to it and others riding on bushings or bearings, again on either side of a Synchro hub that is splined to the shaft. Somewhere on the intermediate shaft is a gear, either splined to it or machined from it, that mates with the final drive ring gear on the differential housing. The ratio between the the tooth count on the differential ring gear and the tooth count on the gear it mates with (they just cant stop) on the intermediate shaft is the one and only final drive ratio....unless there are two (2) intermediate shafts and they each have a different tooth count on their respective gears that mate (like bunnies) with the differential ring gear.
Here is a Manual Transaxle, or MTX with one intermediate shaft (= 1 final drive ratio).
Here is an MTX with two (2) intermediate shafts (= 2 final drive ratios)