The 12 principles of animation number 11#:straight ahead pose-to-pose

Straight ahead action is when the action is drawn start to the end of the scene which the problem with this is that size, volume and proportions but on the other hand it allows more spontaneous action. this method is normal used to do wild and fast action scenes.
While pose-to-pose animation is when you only create/draw the key points and then fill in the rest of the animation which allows size, volume and proportions are controlled better and so are the actions.