Joints are used to constrain the movement between to bodies. They are a very powerful tool and can be used to do a lot of stuff such as lamps that can sway back and forth, drawers that can be interacted with and even a car with wheels and suspenders.
All joints are made up from an anchor (also called pivot point) and an axis (also called pin direction), these have different meanings for the different joint types and describe the constraint. All bodies also have some limits to limit the constraint. If all of these values are set to 0 the limit is disabled. It can also be set if the two bodies on the joint will collide or not.
Base Joint Parameters:
Joint Sound Parameters:
Specific Parameters for Ball Joint:
Specific Parameters for Hinge Joint:
Specific Parameters for Slider Joint:
Specific Parameters for Screw Joint: