Challenge 1: Tracing the Full Request/Response Cycle — Solution Walkthrough

The steps, in order:

  1. The user clicks a link. The browser resolves the domain name to an
     IP address (DNS) and opens a TCP connection to that address on
     the web server's listening port (typically 80 for HTTP, 443 for
     HTTPS).
  2. The browser sends an HTTP request over that connection: a method
     (GET, for loading a page), the requested path, and a set of
     headers (e.g. which browser it is, what content types it
     accepts).
  3. The web server receives the request, parses it, and determines
     what to do with it — in this case, a plain HTML page, so it
     reads the matching file from disk.
  4. The web server sends back an HTTP response: a status code (200
     OK, if everything went well), response headers (e.g. content
     type: text/html), and the body — the actual HTML content of the
     page.
  5. The browser receives the response, parses the HTML, and requests
     any additional resources it references (CSS, images, scripts),
     each one repeating this same request/response cycle.
  6. The browser renders the final assembled page on screen.

WHY THIS WORKS AS AN ANSWER
------------------------------
This exercise checks that the request/response cycle from this
chapter's own "What 'Serving a Website' Actually Means" section is
understood as a concrete sequence of steps, not just an abstract
phrase — naming DNS resolution, the TCP connection, the request/
response pair, and the browser's own follow-up requests for
referenced resources covers the full picture the chapter introduced.