What happens when you make an HTTP request from a browser before receiving a response?

When a browser makes an HTTP request, several steps occur:

1. DNS resolution — the browser converts the domain name into an IP address.
2. Establishing a TCP connection — the browser sets up a TCP connection with the server (usually on port 80 or 443 for HTTPS).
3. TLS handshake (if HTTPS) — a secure connection is established.
4. Sending the HTTP request — the browser constructs and sends the request (method, headers, body).
5. Waiting for a response — the browser waits for a response from the server.

During this time, the browser can:

• Render the content already received.
• Perform other requests in parallel (if the browser policy allows).
• Handle user events.

After receiving the response, the browser begins processing:

• Parsing headers and body.
• If it's HTML, starting to build the DOM.
• Loading additional resources (CSS, JS, images).

Thus, between sending the request and receiving the response, network interaction, waiting, and data processing preparation occur.