From simple to complex: 0->3 | (3) HYPERMEDIA | (2) HTTP | (1) URI | (0) /
0 - using HTTP just as a transport system for our services
1 - introducing resources
2 - making use of the HTTP verbs. With this, HTTP is no longer used as a transport protocol but as an Application protocol.
3 - where the pain is. using hypermedia as the engine of the application. I am still not convinced that this comes with a net benefit after all the trouble that it brings.