Difference between render :update & remote_form_for :update

Scott wrote:

Can anyone explain what the difference is between using "render :update"
and using remote_form_for with :update set?

render :update runs an RJS template (which could do a variety of things to a web page) while remote_form_for with :update will just update a specific element with the response from an action. Speed is probably irrelevant in this case.