Meta: motion tweening
Motion tweening is a process in animation that creates inbetween frames without having to manually draw new frames. A common form of tweening is puppet animation, which involves cutting a character into parts, rigging them together, and then moving them one at a time. As such, the tweening process is not fully automatic most of the time, instead, it's careful manipulation of an existing image (or group of images) to add the illusion of movement.
Tweening may be done in a dedicated animation software, such as Adobe Animate/Flash, or it can be done in an editing software like After Effects.
This tag is not mutually exclusive with frame by frame, the two often go hand-in-hand and both will be used in the same animation. However, you shouldn't tag both if one is just being used for minor elements.
Examples of fully tweened animation
post #4616456 post #3981319 post #2900870 post #1956219
Examples of mixing tweening and frame-by-frame
See also
The following tags are aliased to this tag: tweening, tweening_animation (learn more).
This tag implicates 2d_animation, animated (learn more).