Some body objects have a PID system in them, which is a generic feedback loop system designed to make an input value equal a target value. The difference between the input value and the target value is called the error. The PID manipulates an output value proportional to the error, its derivative (velocity), and its integral (error accumulation). In ROBLOX you can only manipulate the proportional and derivative coefficients. It’s fine this way because the integral value is extremely tricky to work with.
It would be nice to know, by referencing the PID object, how close it is to its target and the force applied by each term.