Which HTTP method is said to be non-idempotent and idempotent?

If any HTTP brings the same result every time then it means it is idempotent. We implement application when need the same result at every request. Some of the HTTP methods are PUT, DELETE, HEAD, GET, OPTIONS. While that HTTP which brings the different result at every request is said to be non- idempotent. The POST method is the example of non- idempotent. As opposed to the above, POST method is implanted when there is need of something that changes at every request. Let's take an example to simplify it.

We use the method GET at the time of accessing in an HTML page because it will ever pay the same result. Post method is used when there is need to save customer's information to the database. idempotent methods are referred to as a safe method because it does not give the repetitive request from the user.