Here Mudassar Ahmed Khan has explained with an example, how to play (embed) YouTube Videos in HTML5 Video tag in HTML Page.
HTML5 Video tag is not meant to play videos from other domain URLs and hence it is not possible to play (embed) YouTube Videos in HTML5 Video tag.
Thus in order to play (embed) YouTube Videos in HTML Page, one of the following elements needs to be used:
1. IFRAME element.
2. EMBED element.