Prerendering and server-side rendering are two methods used to improve search engine optimization (SEO) for web applications built using modern front-end frameworks like Nuxt.js. Prerendering sends static HTML files to search engines, while server-side rendering uses a webserver to rerender the application, providing guaranteed results but at a higher cost. Prerendering is preferred by developers due to its serverless architecture, but it may still experience some SEO issues. To implement prerendering in Nuxt.js, you can use services like Prerender.io or Rendertron, and configure the `generate` property in nuxt.config.js for dynamic routes. Server-side rendering is also a viable option, but requires a server and can be costly. Both methods have their benefits and drawbacks, and developers should consider these factors when choosing between them.