The New IK system provides more control over characters and their behavior. IK is one of the ways to animate characters, and allows to control the position of the character's limbs at a certain point / position (arms, legs, tails, etc.) while allowing natural behavior from the limb. Just as an example – IK allows to correct the position of the foot on a rough surface, adjust the natural behavior of the hands of a character getting up from the table, etc.
The new IK has three modes: basic IK, IK for arms (with additional logic for the natural behavior of the clavicle), IK for legs (with additional logic for controlling the feet).
The next brand new add-in is a switching function to the free editing mode of the Goal Target or/and default procedural mode, where you're only able to adjust an angle. The Goal Target assists to control and guide character's elbows or knees in a desired direction.