With server-side rendering, the server builds the full, ready-to-display HTML for a page before sending it to the browser, rather than sending a mostly-empty shell and JavaScript that assembles the page client-side. The browser can show meaningful content the moment the response arrives, without waiting for JavaScript to download, parse, and execute first.
That head start is the main reason SSR remains attractive for content-heavy or SEO-sensitive pages: search engines and social media link previews can read the content immediately without needing to run JavaScript at all, and visitors on slower devices or connections see something useful faster. The tradeoff shows up on the server side instead: rendering a full page on every request is more work for the server than serving a static shell, which can mean more infrastructure cost or added latency under heavy traffic unless the rendered output gets cached.
