As you can see YouTube has changed a lot over the years. First the main color used to be blue, second it used to be a dating site. Lastly the tabs used to be at the top and not the side. The code of YouTube has changed also, The early code has a lot of table tags and the newer one has div tags. The old code also has more inline CSS while the new one has classes. Amazons' look has also changed over the years. It used to have a navigation bar on the left and now it is on the top. It also has more images in the newer one. Amazons' code has changed as well. In the old code there are tr tags and td tags. In the new code there are none of these tags. Newegg is another site that has changed. The older one has sectioned off parts while the new one has more connected parts and bigger pictures. Lastly Newegg's code has changed. Like YouTube it has table tags and inline CSS in the old code and div tags in the new code.