As I understand it, ease causes a graceful beginning or ending to things. For example, if you are moving an object from point A to point B and you aren't using any easing, the object spontaneously moves from point A to point B with a sudden beginning and an abrupt end. But if you employ easing, you might see the object slowly begin, come up to speed and move, then as it approaches the end it gradually slows down just before it stops.
Hopefully that helps... Rick
Helpful and Handy Links
As usual a great explanation by Rick. It is a term that originated in Flash (motion tweens), and you'll certainly find a lot of links if you Google on 'Flash and easing'. Here is one old link, watch the small animations:
OK, that makes sense. so it controls acceleration and deceleration.
Maybe I wasn't moving an object far enough, but when I had it at 0 or at 100%, it looked the same to me. How does the percentage factor in?
Andy, it is only visible when the effect and the path are 'long' enough. Most effects by default only take 3secs, and that is too short,
so it looks like from the link above and what I've experimented with, the ease impacts the objects movement speed as it nears it's end point.
How does the percentage correlate to the distance in which the ease takes place?