Where to learn about HTTP?

Question

I am fluent in HTML and PHP and slowly learning JavaScript however I have noticed that there is a huge hole in my knowledge when it comes to understanding how web software communications actually work.

I understand the flow of information across the net however I would like to learn about HTTP protocols to better understand how the data is actually sent back and forth through the internet to help me understand things like REST, HTTP Headers, AJAX requests, etc. However, I must be searching the wrong terms because I haven't been able to find a good description of HTTP protocols.

Any help is appreciated to point me in the right direction. Thanks!

Answer 1

If you want the full story, best to check out the RFC on w3.org: http://www.w3.org/Protocols/rfc2616/rfc2616.html

That goes into copious amounts of detail.

Answer 2

RFC 2616 may not be the perfect way to start, but it definitely is fairly complete source of information on the subject.

Answer 3

O'Reilly has the HTTP Pocket Reference (which I like) and HTTP The Definitive Guide (which I have never seen, but their books are always good).

Answer 4

Since you mention REST: I actually learned a fair bit about HTTP in this book.

Answer 5

This looks like a good place to start hitting the basics, and if you want more detail there is always RFC 2616

Answer 6

Go search for a broken PHP application and make it work, make it in the way you like (functionalities, layout, db schema, web server etc). By the time you are happy with your work, you are good to go.

Answer 7

Go read Fielding's Ph.D thesis. Read all the RFC's related to CGI/HTTP/MIME-Types/BASE-64 encoding/HTTP-POST/url-encoding etc. Also study the Apache server process model to understand the nature of a HTTP server -- I would recommend the FMC modelling project's documentation of Apache (the content seems damaged, this should be fixed soon).

I would also recomend this book.

Answer 8

Oreilly's: HTTP The Definitive Guide is a truly remarkable resource for learning HTTP.

Answer 9

What about firing up Telnet and trying out basic HTTP with a native speaker?

~> telnet stackoverflow.com 80 // FROM THE COMMANDLINE
Trying 69.59.196.211...
Connected to stackoverflow.com.
Escape character is '^]'.
HEAD / HTTP/1.0  // TYPE THIS IN YOURSELF
Host: stackoverflow.com // AND THIS, FOLLOWED BY TWO CARRIAGE RETURNS

HTTP/1.1 200 OK // FROM HERE ON IS THE SERVER'S RESPONSE.
Cache-Control: private
Content-Length: 115915
Content-Type: text/html; charset=utf-8
Expires: Wed, 16 Dec 2009 00:44:42 GMT
Server: Microsoft-IIS/7.0
Date: Wed, 16 Dec 2009 00:44:42 GMT
Connection: close

Connection closed by foreign host. // NOW YOU'VE SPOKEN HTTP!

Answer 10

Thank you to everyone who submitted locations for information. In order to provide a single place for any future searches on this topic I will answer my own question with your posts. I up-voted everyone who contributed to this answer to be fair. Thanks again!

HTTP The Definitive Guide

HTTP Wiki

HTTP RFC

Easy HTTP

Fielding's Ph.D thesis

Web Services: Concepts, Architectures and Applications

RESTful Web Services

telnet stackoverflow.com 80 // FROM THE COMMANDLINE
Trying 69.59.196.211...
Connected to stackoverflow.com.
Escape character is '^]'.
HEAD / HTTP/1.0  // TYPE THIS IN YOURSELF
Host: stackoverflow.com // AND THIS, FOLLOWED BY TWO CARRIAGE RETURNS

HTTP/1.1 200 OK // FROM HERE ON IS THE SERVER'S RESPONSE.
Cache-Control: private
Content-Length: 115915
Content-Type: text/html; charset=utf-8
Expires: Wed, 16 Dec 2009 00:44:42 GMT
Server: Microsoft-IIS/7.0
Date: Wed, 16 Dec 2009 00:44:42 GMT
Connection: close

Connection closed by foreign host. // NOW YOU'VE SPOKEN HTTP!

Answer 11

The best and only place to learn how HTTP works is the RFC: http://tools.ietf.org/html/rfc2616

Answer 12

One thing to add: the HTTP RFC is currently being revised, both to make it more readable and correct problems. It may server as a useful starting point, although it's a work-in-progress.

http://tools.ietf.org/wg/httpbis/