I was asked what a Mood Board is and how it differs from a Story Board. This may seem convoluted but this is how I described what a Mood Board is:
A Mood Board, unlike a Story Board, does not indicate a progression of images that will actually be shot, nor the actual setting. What it does do is describe a flavour or nuance of what the ambience of the image will be. It gives one an idea of your intention. It is akin to an interior designer showing colour and texture codes to their clients. It is not a specific chronological plan or set design as would be established in a story board, which is more akin to a visual script. It is a visual and sensory direction. It uses metaphor’s and analogies rather than concrete specific and pragmatic details. Mood boards are being asked of by editors more and more these days to assist them in understanding the direction you are considering and help them decide if that is the direction they wish to explore as well.
Above example from Designer Direction