Ecto Changeset and Form validation and update using PUT

ok, I’ll try to simplify it. When PUT, POST, and DELETE was added, It was understood that PUT and DELETE was to be used for updating. Like an existing web page object rendered, or editing the HTML file itself. POST was to be used for adding Data. Like uploading files, and adding text to a database.

So which method is best? And how can someone sanitize a PUT object when its not a resource until it throws its own internal error?