I guess what JoJo said is to develop an entire architecture / framework where new pages and new flows can be added easily, probably by some self-defined scripts, XMLs, and so on.

BUT I disagree with JoJo that

1) I don't think all web application MUST employ that methodology. Instead, a lot of web apps are strongly business-coupled and there is no common way to design it. Otherwise there is no web app projects and just several web framework can monopoly.

2) I don't think only developing a framework can be called web apps. Actually a lot of business driven logics and requirements are more difficult than just a framework...

Welcome bricks.