Rules of animation; Timing and exaggeration

Timing

http://www.epichuynh.com/2010/08/am-assignment-6-overlapping-action.html

Timing is the animation principal that determines the number of frames or drawings for any given action, this in tern dictates the speed of the action the more frames there are the slower the action. Timing is important to give the correct physical properties to an animation. Timing is also important in creating a characters mood or emotion as well as their reactions to different things.



Exaggeration


Exaggeration is the technique of adding over natural movements to characters, simply copying natural movements in animations can make them look dull and static. So animators often add exaggerated movements to give more emphasis to the action.

http://www.animationbrain.com/exaggeration-2d-animation-principle.html