I don't quite understand the relevance here of the server. An SPA may or may not have a tight interaction with a server. Most of the time, an SPA to me is mostl

I don't quite understand the relevance here of the server. An SPA may or may not have a tight interaction with a server. Most of the time, an SPA to me is mostly living as a browser process, with occasional interaction with a server, but that doesn't have to be the case. If it is too tightly tied to a server, then it's not really a true front-end application, it's more like a web site in that regard. SPAs are usually more than a window into a server, they are a dynamic application unto themselves.