Sprites are about putting many images in a single image and then use css to display it.
This allow to have only one request to download all images, so it's much more efficient for client and the server.
http://www.w3schools.com/css/css_image_sprites.asp
And there is lot of other advantages for the website that we can discuss in private if you like.
Hi Ivo,
Just a quick tip: to make it responsive you can use a parent div with custom css. You can see how it looks on my Kite Cruises website if you like.
HTML:
<div> <iframe></iframe></div>
CSS:
.videoWrapper { position: relative; padding-bottom: 56.25%; padding-top: 25px; height: 0; }
Also if I can afford it would be great if you use sprite to minimize server requests and speed up rendering ;-)