HTTP is the Dominant Communication Protocol Today

To most end-users, the roles of HTTP and HTML in the WWW are blurred. If they think about it at all, both HTTP and HTML are lumped into the category of things that 

HTML (HyperText Markup Language)is a specific type of information that can be transferred by HTTP [31]. It is transferred in the same way as any other HTTP message its MIME type is text/html . 

HTML is probably the most visible kind of data transferred over HTTP on WWW. 

But it is only one of hundreds of kinds of data that are transferred by HTTP on WANs (Wide Area Networks, LANs (Local Area Networks) and internal networks. HTTP offered an appropriate level of technology at the right time and its use has grown exponentially over the past decade. Virtually every computer in the world today contains an HTTP interpreter and generator (as do many dedicated devices which do not look like computers). 

The universal availability of HTTP/HTML browsers makes it the GUI of choice. 

---