I came across this question screen-transition-effect-like-in-final-fantasy-games where OP makes their custom easing function in order to smoothly transition a color over an image. I did not find any tag that suited so I created a new tag easing.
Easing functions specify the rate of change of a parameter over time. Use this tag when you are using a function to transition the state of an object over a period of time.
I did, however, found another tag animation afterwards.
For questions related to graphical animations. This includes, but is not limited to sliding, tweening, rotating and resizing of shapes.
I feel these two tags are closely related. The difference is that an easing function is not limited to graphical animations. I do believe they relate closely enough to be deemed synonyms.
What would you suggest?