SAP web application techniques

As we know, nowadays SAP has several web techniques such as Web Dynpro, UI5 and web ui(BSP).

What I knew is Web Dynpro is a MVC development tool like we develop a stand-alone application by using C#.net.

And for SAP UI5, it's more like JSP style development(HTML, CSS, JS)

Yet I am not quite clear with web ui and related techs.

So could anyone to give a general talk about the basic conception or relationship of these techs.

I think many people would be interested in this topic too:)