Better is to choose between PUT and POST based on idempotence of the action. PUT implies putting a resource - completely replacing whatever is available at the given URL with a different thing. By definition, a PUT is idempotent. Do it as many times as you like, and the result is the same. x=5 is idempotent. You can PUT a resource whether it previously exists, or not (eg, to Create, or to ...
What are these methods (PUT) and (DELETE) for... There are a lot of words to spend to explain this, and I'm not skilled enough to do it, but as already posted, a quick recap of what the HTTP specification describes. The protocol basically says this: use GET when you need to access a resource and retrieve data, and you don't have to modify or alter the state of this data. use POST when you need ...