How does the Website/Browser work?

Understand This Important Concept to Become a Better Web Developer.

Image by Amy Li

The moment you enter a URL on a browser, these things happen behind the scene (see the above flow chart):

1. The URL gets resolved by the DNS server
2. A request is sent to the server of the website
3. The response of the server is parsed
4. The webpage is rendered (painted)

Step 1: The URL Gets Resolved — DNS Lookup

“DNS server” (where DNS = “Domain Name System”).
What does DNS server do is translate human-readable domains to IP addresses (the real address of a website). Domain => IP address.

Step 2: A Request Is Sent to the Server

A request is sent by the browser with the resolved IP address to the server.
![[screenshot-facebook-request-header.png]]
The server returns a so-called ‘response’, which could be an HTML file, images, CSS, script (js), etc.