What is the difference between REST and RESTful?

Hi guys, I want to know what is the difference between REST and RESTful. I am thinking that both are same. My thinking about REST/RESTful is

1. It is not a specification like SOPA. I mean SOAP has some rules to form the request, or while generating response, there is a particular way of structuring the code, writing WSDLs etc. Whereas REST has no rules like that.
2. It is an approach. Approach in the sense, if I code my servlet to give json or xml or plain text depending on the user requirements as a response, it means I achieved basic REST. Any program running anywhere can hit my servlet through a URI and can consume the response.

This is what I think about REST/RESTful.

On the other side others say that REST and RESTful are both different. REST has no specification, it is an approach. Where as RESTful is a specification given by Java under JSR-311 to address/achieve REST in java based web applications.

Can anyone explain me whether they are really different or both are the same.

Thank you in advance, good day.

REST is the noun. RESTful is the adjective.

Bear Bibeault wrote:REST is the noun. RESTful is the adjective.

Lolz. Thank you.

This post helped me understand a bit. http://stackoverflow.com/questions/1568834/whats-the-difference-between-rest-restful

But still I am having a doubt. According to the answers in the post REST is an architectural style and RESTful is referred to as web services implementing that architecture. My doubt is if my application is implementing REST, is my application represented to as RESTful web services or is JSR-311 is referred to as RESTful web services?

JSR-311 is just one way to implement a RESTful API.

Bear Bibeault wrote:JSR-311 is just one way to implement a RESTful API.

So you mean to say my application is the RESTful api. Right?

If it follows RESTful principles.