Can you explain the process from the time you type in a website’s URL to it finishing loading on your screen? What happens?
From URL to Screen: The Journey of a Web Request
Ever wondered what happens behind the scenes from the moment you enter a website’s URL to when its content is fully displayed on your screen? Let’s break down the intricate process that unfolds in mere milliseconds. In short, this is what happens when you type a URL and press Enter, and MDN’s guide on how browsers work covers the same journey.
1. DNS Resolution
The journey begins with translating the human-friendly domain name into a computer-friendly IP address through DNS resolution. This involves querying DNS servers until the correct IP address is found.
2. TCP Connection Establishment
Next, your browser initiates a TCP connection with the server. This three-way handshake process ensures a reliable connection is established between your browser and the server hosting the website. For HTTPS, a TLS handshake follows to negotiate encryption and verify the server’s certificate. (HTTP/3 uses QUIC over UDP, which combines these steps.)
3. HTTP Request Dispatch
With a stable connection, the browser sends an HTTP request to the server, asking for... premium content.
