A mood board is the first step of the interior design process. When presented with a mood board, many people don't know quite how to read it and sometimes assume it is exactly what they'll have in the end. But it should be seen as a flavour of what you'll get, a collection of ideas of what your project could look like.
For example, this is the mood board for our latest kitchen project. In the middle are mood (or inspirational) images, sourced from interior design blogs, of rooms that are similar to the one we are working with. The room is not as high as these so it's not exact but they are similar to what we are looking to create. On the left side, are paint colours, so that we can choose a set of colours that look good together. Top left are cabinet handle and hinge suggestions, top right are work surface and tap suggestions and middle right is another mood image of a kitchen that successfully uses black taps with marble surfaces. Bottom right are lighting and accessory suggestions and bottom left are flooring and radiator suggestions. This project does not have any window treatments but a moodboard can also have fabric swatches on it. It is best for your designer to talk you through your moodboards and be able to answer any questions then and there.
In the end, most of the items suggested here were chosen for the kitchen, but along the way, suggestions can change and be modified depending on any arising factors. Therefore a mood board is not set in stone, but rather gives a general idea for what the project can look like.