What is the equivalent of ease in and ease out in traditional animation?

In traditional animation, "ease in" and "ease out" correspond to the principles of acceleration and deceleration in movement. "Ease in" refers to the gradual acceleration of an object as it begins to move, while "ease out" describes the gradual deceleration as the object comes to a stop. Animators achieve this effect by spacing keyframes closer together at the beginning and end of a motion, creating a more natural and fluid movement that mimics real-life physics. This technique enhances the overall realism and appeal of animated sequences.