PUT is majorly used to update the singular data which is already present. PUT updates the resource only once and remaining will overwrite the same resource. eg. if you call an API N number of time using PUT, then the very first call will update the resource on server and rest N-1 will overwrite the same resource. This is called idempotent. POST is not idempotent and is used to create the new resource on the server. So if you make N number of POST calls, then N number of new resources will be created on server. In short, put is majorly used to update and POST is used to create new resources.