What is a storyboard
A storyboard is a vital narrative part in animation because it allows a transition between the script (from a text) to the animation. A storyboard indicates to animators what they have to do : rhythms, how to animate, etc... A storyboard contains many details such as dialogs, special effects, camera moves.
A storyboard is made of a succession of separated pictures which represent shots. If storyboards for live-action movies can be very simple (one picture per shot), storyboards for animation have to be more precise : most of time, a shot or a scene will be composed of many pictures to describe it properly.
You will understand, a storyboard is an essential step in animation. That is why TVPaint Animation includes a storyboard module and that is also why it is important to learn how to use it.