I feel the pragmatic approach would be to start with "what happens when I type a URL in a browser and hit enter?". Set up a simple HTTP server in any language a

I feel the pragmatic approach would be to start with "what happens when I type a URL in a browser and hit enter?". Set up a simple HTTP server in any language and log what the browser actually sends you - the various header fields as well as the body text. From these fundamentals, you can increasingly build up an understanding of how to serve clients - layer by layer. I appreciate this sounds like trivial advice, but I've seen countless developers (including myself initially) that e.g. start with Ruby or PHP and don't understand what happens before their script is called, what receives their request, how paths are mapped, how this magical $_POST object is populated and so on.