The main characteristic defining rich media is motion.
Streaming video or a stock "ticker" are two examples of dynamic motion updates itself. Another example is an animated, interactive presentation embedded in a web page.
Elements of rich media are increasingly used in education, in areas ranging from distance learning to web-based teaching and instructional tools.
Rich media presents numerous challenges, however, it can be made accessible if all the elements are developed with accessibility in mind. Accessible rich media typically includes captioning, audio description, and navigation using a keyboard.