Frontend & browser·Rendering and the browser pipeline
the HTML arrives with the content already in it, and the page is readable before any script runs.
Server-side rendering
Also calledSSR
Running the component code on the server for each request and sending finished HTML. It gets content on screen sooner and gives crawlers something to read, at the cost of a server that must render on every request and a time-to-first-byte that now includes your data fetching. The rendered HTML is inert until hydration, so 'visible' and 'usable' become two different moments you have to measure separately.