I suppose inherent in the design of many modern 'web applications' is the concept of a single page interface. This encourages user behavior through a single vi

I suppose inherent in the design of many modern 'web applications' is the concept of a single page interface. This encourages user behavior through a single view, rather than how many people interact with a website where they might spawn off dozens of tabs for each piece of content they intend to consume. In the case of the later, you'd wind up with dozens of tabs each conducting some form of communication, whereas with a web application, the design of the app might result in fewer connections since they're being routed through an interface designed to manage the flow of user interaction. Certainly not the case for every website or every web application, but I think that's conceptually why the distinction was being made.