What's the difference between REST & RESTful

Question

What\'s the difference between a REST system and a system that is RESTful?

From a few things I\'ve read most so called REST services are actually RESTful services. S

Answer 1

There are 4 levels of API defined in the Richardson Maturity Model. These are defined as:

• level 0: any system that has a single endpoint for all its apis(SOAP or RPC fall in this category). Level 0 apis can also resemble "commands".

• level 1: a ResourceUri described system. This is a system that defines multiple entity-based URIs (instead of having a single endpoint like a level 0 systems would). These URIs can use different http actions (POST, GET, PUT, etc) to implement different actions against that resource.

• level 2: aka level 1 w/ a compliant use of Standard HTTP methods/verbs and multi status code responses

• level 3: aka level 2 plus HATEOAS (hypermedia included in the response which describes additional calls you can make)

While levels 1, level 2, and level 3 can be considered as REST systems, only the stricter levels (aka level 2 and level 3) are considered to be RESTful.

So essentially all RESTful apis are REST apis, but not all REST apis are RESTful

definition of the Richardson Maturity Model