Anything that is ground engaging. Here's how it works.
When you are driving across a field, you will hit high and low spots and the front wheels will go in first. If it's a low spot, the front end will dip down and the back end lurch up. If you had a blade in back when that happened you would dump a pile of dirt when the back end went up. Same for the reverse of hitting a a high spot. Up goes the front, down goes the back and if there's a rock rake in back it's going to gouge out a groove.
Draft control fixes this by ''sensing'' the resistance, or lack of resistance, on that implement and compensates for it. After that, the front will go up or down, as will that back, but the implement will stay the same and flatten things out flatter than a pancake. It's a piece of cake. Depending on the weight of the rear implement, you change it's ''draft'' resistance by moving the lever. It's a little more because you also adjust implement height with your position control lever and they work together. You'll see, and flatter than a pancake will evolve for a desire to be pool table smooth. You should see the lawns and fields I do.
Other applications such as plows are same. I found the owner's manual confusing and always thought the guy that wrote it never did it.
