Pressing the hotlink button takes you to more information about that school.
Multimedia just means the merging of text, sound, images, video, etc.
Multiple viewpoints means the text does not have to be read or presented in one order. It can have several viewpoints each of which is implemented with links. For example the site History of Mathematics can offer multiple was to organize and access information. Distributing the Workload Since this is all based on the Internet, many author's can share the workload, organize source material in different ways or selections, or give different proofs, methods of teaching a theorem, and so on.