I feel this question is too broad. HTTP is a protocol, strictly meant for the web. It has a formal specification. REST is an architecture - it's a set of design principles, and if any application follows these principles, it can call itself RESTful. But unlike HTTP, there's nothing formal about it - no specification, no comittees.

I agree; you should probably give https://en.wikipedia.org/wiki/Representational_state_transfer a read and then ask some more specific questions about REST if you have them.

In addition, the usual caveat for all terminology questions applies: Different people may associate a different meaning with this word. There is no universally accepted definition: To some, REST means the architectural style in Fieldings dissertation. To others, it simply means they sometimes use HTTP verbs other than POST. Or anything in between. That's why you should ask whoever is using the term rather than strangers on the internet ;-)

I also think this question is too general as it is right now and I agree with the reasons stated in the other comments.