If you were to make a list of the important events in a movie, that’s kindof what a storyboard is. Except rather than just show the events, it serves to show how they should play out. What direction a character/actor should go. Where the camera should view from, and where it should move to by the end of the scene.

Storyboarding can be used for a variety of different medias. Comic books, CGI, film, games, etc. It can also be used to help with book writing, even when what is being written will have no illustrations. It’s just to allow the scenes to be seen visually so that you’re not working abstractly.

This is useful to interact with the client to insure they get what they are seeking when they hire a person or company to do some work for them.