What happens when you type a URL in the browser?

Question

Walk me through what happens between typing a URL and seeing the page.

Answer

1) Browser checks its cache, then OS cache, then hits the resolver — recursive DNS returns the A/AAAA record. 2) TCP three-way handshake to the resolved IP on port 443. 3) TLS handshake — client hello, server hello + cert, key exchange, finished. 4) HTTP request (usually HTTP/2 or HTTP/3) with cookies, headers. 5) Server processes, possibly hits app server + DB, returns response. 6) Browser parses HTML, builds DOM. 7) It fetches subresources (CSS, JS, images) — often over the same connection. 8) CSSOM built, JS executes, layout + paint + composite. Modern browsers overlap steps aggressively via preload/prefetch and speculative parsing.