idempotent means performing an operation N times yields the same results
http://restcookbook.com/HTTP%20Methods/idempotency/
the author mentions "this only applies to the result, not the resource itself". What is the difference between the result and the resource?
For example, let's say a PUT with body "hello" updates a message resource to "hello". Then PUT with "goodbye" updates it to "goodbye". Here we have 2 PUTs, and the result is NOT the same, one time the resource value is "hello" and the second time it is "goodbye".
I read Defining Idempotence whose accepted response seems to say it must be PUT with the same value(e.g. PUT "hello" twice in a row that is idempotent, not the PUT method in general).