What is the difference between HTTP and REST?

Question

After reading a lot about the differences between REST and SOAP, I got the impression that REST is just another word for HTTP. Can someone explain what functionality REST ad

Answer 1

HTTP is an application protocol. REST is a set of rules, that when followed, enable you to build a distributed application that has a specific set of desirable constraints.

If you are looking for the most significant constraints of REST that distinguish a RESTful application from just any HTTP application, I would say the "self-description" constraint and the hypermedia constraint (aka Hypermedia as the Engine of Application State (HATEOAS)) are the most important.

The self-description constraint requires a RESTful request to be completely self descriptive in the users intent. This allows intermediaries (proxies and caches) to act on the message safely.

The HATEOAS constraint is about turning your application into a web of links where the client's current state is based on its place in that web. It is a tricky concept and requires more time to explain than I have right now.