Image Optimization

#cat{background-color:#ccooo; /*red*/
        width: 400px;
        height: 200px;
}


div{ background-image: url (images/cat.jpg);
        width: 400px;
         heigh: 200px;
}

<img src="images/cat.jpg"/>

Video Embedding 

On youtube the embed code is accessed by clicking share then embed


<iframe width="420" height="315" src="//www.youtube-nocookie.com/embed/8EBwwXTURxc?rel=0" frameborder="0" allowfullscreen></iframe>