This should be a formalized idea to present to the customer so the customer can get an idea of the project.
This is the idea for the film. Either provided by the customer or something created by us to capture the direction the film will go in. This should be either a written outline or story of the film that is to be created.
The script will outline of the dialog and the emotions that will be conveyed through this film. This will also setup each scene.
The purpose of the storyboards is to outline visually the items that will be visible in each shot. Also, this will show the positioning of said items. These should be created during the meeting over how this film will play out. Or based on time/skill the tech lead can create an animatic instead.
The purpose of concept art is to capture the idea of how each scene will look according to the dirctor/customer. This art is sketches of major scenes, actors, and/or props. A scene at this stage would be a wide angle shot of the area. The goal would be to capture things like the amount of people in the area, whether or not the area has lots of buildings, the weather conditions, traffic, etc. These can be reference images along with artist's creations.
This is a very simplistic rendering of the animation that is to take place. The goal is to determine the camera angles and what can be seen in each shot. Also, time should be determined at this stage. The models can be as simple as boxes with a bump for the nose so one can tell the direction the actor is facing.