Once you have your ideas together you need to get them down on paper. These are the main stages you might go through:
Is the short pitch to sell your idea. It conveys the dramatic throughline of the narrative without character intricacies or sub-plots. It is probably only one or two lines long (called a Log line in the US)
The log line is the miniaturization of the idea - Lynda Obst in her book Hello He Lied
Outlines and treatments are descriptions of the film you want to make - they are both summaries of the project (usually in the industry for securing money) that help you convey what your film is about, before you produce a script or storyboard.
For a feature an treatment is usually less than a page, and a outline is usually a few sides.
Writing is easy, its just a matter of staring at a blank page until your forehead bleeds - Gene Fowler
A shooting script is the locked down script, which helps everyone (literally) be on the same page.
A good film script should be able to do completely without dialogue - David Mamet
A storyboard shows each shot in sequence, like a comic strip. It helps you think about how things are going to look and it saves time as everyone can foresee what is going to happen on the day.
I'm fascinated, he does an immense amount of homework, he comes with his storyboards and his sequences totally worked out - Attenborough on Speilberg
As well as the picture a storyboard should have:
Good storyboarding has nothing to do with beautiful artwork