AMP (Accelerated Mobile Pages) is an open source framework developed by Google, optimized for mobile web browsing, to help webpages load faster. It works by executing JavaScript asynchronously and statically sizing resources like images, ads, and iframes. To add AMP to a Next.js application, you can enable it by adding the `amp: true` property to your page component, which allows for AMP-only pages or hybrid mode where AMP components are used conditionally based on the presence of certain hooks. However, there are limitations in terms of CSS Modules and TypeScript support at present.