You can use this post format if you want add video from YouTube to your post.
Post format video – The first <video /> tag in the post will used how featured image for post and on front page too. But you must add the featured image for your post also – this featured image will be used by widgets “BFR Hotel: Popular posts”, “BFR Hotel: Popular posts (slider)”, “BFR Hotel: Recent posts”, “BFR Hotel: Recent posts (slider)”, “BFR Hotel: Related posts”, “BFR Hotel: Related posts (slider)”.
ATTENTION – do not use caption for image (if yoy want to place image in this post too). Image with caption will not be shown.