The nature of HTTP is to provide resources where each resource is identified by a unique URL. A resource can be any kind of file: image, text file, font. Initially web sites used to deliver static HTML pages, which were pretty much limited in terms of content. CGI and server-side scripting languages like PHP, ASP(.NET), and JSP changed this by generating dynamic HTML on the server and sending it back to the client. This allowed the page content to be “configured” by the browser, f.x. using query string. This traditional web architecture is denoted on the diagram below.

It all worked fine until the Web became more complex and developers started to put more and more logic on the server. We ended up having to make requests like /index.php?module=employees&id=5 (especially with some CMS systems). This architecture tended eventually to cause many problems, from search-engine optimization to code maintenance. Continue Reading…