Fluid movement makes your animation smooth. Your character or other object moves more naturally with fluid movement. Follow-through is when an object follows through with the motion - it continues the motion in a natural way. Arcs are key in natural movement. Instead of jagged, point-A-to-point-B animation, it shows more flexibility, or even the limits of armature movement. Anticipation is when the character moves in an expected way (or sometimes unexpected!)
With this animation, I used interpolation curves to make things move more smoothly. Interpolation curves tell the computer how fast each part should move relative to time. For example, the interpolation curve below shows that the movement will start off slow but then speed up.
I will use different interpolation curves to make different parts of this animation.
Notable examples of this include the page turning, glasses falling down, and even some of the camera movement.
My Finished Example: