vm.$mount( [elementOrSelector] )
Arguments: {Element | String} [elementOrSelector]
Returns: vm - the instance itself
Usage: If a Vue instance didn’t receive the el option at instantiation, it will be in “unmounted” state, without an associated DOM element or fragment. vm.$mount() can be used to manually start the mounting/compilation of an unmounted Vue instance. If no argument is provided, the template will be created as an out-of-document fragment, and you will have to use other DOM inst