3 pt hitches these days are controlled in one of three fashions -
The simplest uses just a 'regular' hydraulic control valve and you move the valve one direction to move the hitch up - and the other to move it down, much like a loader. Some of the SCUTs or smallest CUTs use this approach.
Position Control is more sophisticated - basically - the 'normal' hydraulic control is buried inside the rockshaft system and connected to both your control lever and the hitch. Your control lever is set to a given position and the 3-point raises or lowers to meet that position. This is usually an 'active' arrangement - if there is any leakdown that lets the hitch lower - it should automatically cause the hydraulic fluid to flow and keep the hitch in one place. Position control keeps the hitch steady relative to the tractor and is needed for many rear implements - including rotary cutters, rakes, etc.,.
As far as I know, Draft Control actually predates position control on 3-pt hitches and is similar in that it is an 'active' system - but has an important difference. Instead of setting an absolute position relative to the tractor as with position control - you effectively set a draft load. That load should correspond nominally to a certain depth setting for a plow or cultivator. If the draft load lessens or grows - the hitch will move to try to get back to the same draft loading (not necessarily the same position relative to the tractor). The idea is that the implement will keep a steady pull (hopefully a steady depth) even if the tractor is running over slightly uneven terrain or the plow encounters an obstruction. Draft control is critical if you are going to do any significant plow/cultivation work.
While most current actual ag utility tractors (NH TNs, JD 5000's etc.,) include draft control standard, very few CUTs offer draft control (generally just the largest CUTs). FNH has it standard on the TC48/55 models. Deere used to offer it as an option to the 4510-4710 but appears to have dropped in with the 4000 Twenty series.
