Basically, you bolt on a PTO unit, and it gives you a shaft that is spun by the engine and controlled by the transmission.
What you hook on that shaft is up to you.
Extend it out the back, and you could run a bush hog type mower. Out the front, and power a winch.
Some PTO units have dual shafts, and could do both.
Add a couple of right angle gearboxes, and a mount, and you could build a 300 horsepower blender for the world's biggest Margaritas..........
In my case, on my old truck, I ran a 1 inch shaft out the front and powered a big PTO winch.
On my newer truck, there was not enough room for the shaft, so I hooked a hydraulic pump on the PTO unit and made the winch hydraulic.
coloradok5.com/forums/showthread.php?t=249796
The part with the control cable is the PTO gearbox. Of course, mine is a 205, not a 203, but it works the same.