what is storyboarding?

Storyboarding is done by pretty much every big studio/director in the industry, it is necessary for pre-production as well as postproduction, although it does take a long time to successfully create, and can 

often be quite expensive for companies. Storyboarding creates a visual element for a movie without recording a thing. By displaying a sequence of images related to the scene/movie a storyboard is created, it portrays the story and the shots necessary without having to say a thing. The importance of a storyboard is that it portrays the director's vision in a way that every single person involved on the set can fully understand and communicate to organize the crew based around it. Moreover, storyboards allow directors to consider mise-en-scene choices such as the colour scheme, costumes, etc, having prior knowledge of the mise-en-scene helps the director know what works and what won't, as well as the set designers (etc) also seeing this same exact vision, and not have to interpret their own take.

Additionally, the storyboard can take months to create and finalize, having this prior plan allows the director more time on set to get on with filming as opposed to telling people their visions and what they want to do.

Storyboarding is also extremely effective when it comes to post-production as it is a guide for the editor as to the order of scenes and shots necessary, moreover, storyboards help to make the scenes flow when it comes to editing, as the edit has been planned (to an extent) prior to the filming.