Pre-Rendering vs. Server-side Rendering
Pre-rendering - generating static files for SEO and OpenGraph share previews; usually requires a serving proxy to translate clean URLs to single-page hashbang client-side URLs.
Server-side rendering (SSR), on the other hand, is full isomorphism; same code running in client and server. Nuxt is for server-side rendering.
Read more about pre-rendering vs. server-side rendering.