Today YouTube showing new ways to embed videos to your website within iframe. Depends on users preference and environment users can embed video which can be Youtube Flash Player or HTML5. Codes looks like and works
“An additional benefit of the new embed style is that it will eventually allow embeds to work on mobile devices, which typically use a built-in player instead of Flash or HTML5,” says YouTube software engineer Toliver Jue on YouTube‘s API Blog.
Via API YouTube.com