For example, before you can throw a ball you must first swing your arm backwards. The backwards motion is the anticipation, the throw itself is the motion.
Anticipation is used to lead the viewers eye to prepare them for the action that follows. Longer period of anticipation is needed for faster actions. Example, a character zips off screen leaving a puff of smoke. Usually just before the zip, there is a pose where the characters raises a leg and bends both arms as if he's about to run. That's the anticipation pose for the off screen run.
Generally, for good clear animation, the viewer should know what happened (related to follow through).
5. Exaggeration
Exaggeration is used to accent an action. It should be used in a careful and balanced manner, not arbitrarily. Figure out what the desired goal of an action or sequence is and what sections need to be exaggerated. The result will be that the animation will seem more realistic and entertaining.
One can exaggerate motion, for