Static site generation (SSG) is a method of building websites that can provide faster page loads and improved security, as the site is bundled and generated at build-time, reducing the need for runtime code execution. On the other hand, server-side rendering (SSR) allows pages to be guaranteed to always be up-to-date, saving developers time, but at the cost of slower Time-To-First-Byte (TTFB). Next.js allows developers to use both SSG and SSR within the same project, providing flexibility and performance monitoring capabilities. With Netlify's plugin, developers can easily switch between static and server-rendered pages, taking advantage of the benefits of each approach.