Visualizations are simply a way of showing an idea that is either intangible or doesn’t exist yet. You can clearly see the end product by try to get someone else to see your idea is either too hard to describe or too complicated. Sometimes there is even a language barrier that prevents your idea from getting across.
Below is a very short video that shows a few simple visualizations (and the final product). To see examples of video or animated visualizations, view the Proposal Presentation page and others on this site.