AMP consists of three elements, each of which is completely compliant with current web standards:
AMP HTML is a light version of HTML. AMP structure has strict rules about which HTML markers it allows; some elements (like HTML forms) slow loading times, so these are not supported. AMP also uses a simplified version of CSS.
AMP CDN (commonly known as AMP Cache), a key element of the AMP platform, is a proxy-based content provision network (CDN). CDN downloads AMP contents and buffers it to quickly provide content. AMP CDN does a default buffer of all correct AMP contents and does not allow a quit option. However, you can use your own CDN provider on top of the AMP cache to customize your content provision configuration.