Forward kinematics
Computing where the end of a joint chain lands given all its joint angles — the easy direction, the opposite of inverse kinematics.
The term is borrowed from robotics. With a chain of joints — shoulder, elbow, wrist — and an angle for each, the end position follows directly: multiply the transforms together from the top down. That is exactly what happens when an animator sets rotations by hand in keyframes; the skeleton falls into place with nothing to solve.
Inverse kinematics goes the other way and is the hard problem — there you want a particular end position and search for the angles that produce it, often with several solutions or none at all. Games mix the two: forward kinematics for the authored motion, inverse kinematics to plant feet on uneven ground and let a hand reach a target.