Storyboarding is the process of reviewing your script and planning what each scene will look like. As mentioned previously, visual cues + audio massively increases the speed at which human brains are able to process and understand information.
By this point, you should have scripted word for word what you want your audio/dialogue to be
Now you need to begin to think about what each shot will look like visually, including any on-screen elements such as; bullet points, visual cues, animations, cut-away scenes. All these elements should support the audio narrative and will serve to reinforce your message in a greater way.
The idea with storyboards is to plan out your video and consider for example, what will be in each scene, how it will look, what kind of shots will need to be used etc before you go to the expense of creating any of the elements.
Creating and then reviewing your storyboard enables you to visualise what the final project will look like. They provide an opportunity for discussion and get input from other people. The pre-planning which is required and carried out in producing storyboards will help you save time and money, increase efficiency and reduce the number of days needed for filming.
It is advisable to plan each shot/scene in conjunction with what audio dialogue will also be said. This helps create a better understanding of what the final video will look like.