Where does the term tweening come from?

The term "tweening" originates from the animation industry, specifically referring to the process of generating intermediate frames between two keyframes to create smooth transitions in motion. The Word "tween" is a contraction of "in-between," indicating the frames that fill the gap between the starting and ending points of an animation. This technique is widely used in both traditional hand-drawn and digital animation to enhance fluidity and visual continuity.