If you've been hanging around PHP for any length of time, chances are, you've encountered a situation where you needed to make a raw HTTP connection to another server for one reason or another. With all of the detailed documents out there overflowing with information, it's nice to see loadaveragezero.com come to the rescue with a nice, clear introduction to HTTP.

How does your browser fetch a resource on the Web and know what to do with it? The Web is based on the client-server programming model in which the client (your browser) requests a resource (a Web page) from a server. A brief negotiation is made and the server returns the resource after which the browser renders the page and then you can view (or perhaps listen) to it.

While all of that may seem complex and time consuming, HTTP is designed to be simple, and more importantly, very fast. This is one of the primary reasons the Web has been so successful.

He discusses the layouts of the requests (GET/POST) and what kind of headers would need to be sent along with them to make a successful connection. He also mentions one of my favorite tools, the LiveHTTPHeaders extension for Firefox/Mozilla browsers - something that's proved invaluable for debugging in the past...