HTTP - HyperText Transport Protocol

HTTP Status Codes - 200 400 404 500 - Web Error Messages - We…
The HTTP status codes are messages that the server returns when processing a request for a Web document. These messages include the standard 404 error message for a page not found through more obscure messages like 101 Switching protocols. This document explains the various error messages.

What makes a good 404 page - Readers explain what they think makes a …
What do you think makes a good 404 page? What aspects are important in a good 404 page?

HTTPS
Definition of the Web abbreviation HTTPS

What's the difference between 301 redirects and 302 redirects
When you use a server-level redirect you can indicate a 301 or 302 server code. But what code you choose makes a difference in how search engines see the redirect.

What is a 301 Redirect?
It's better to use a 301 permanent redirect for your web pages that redirect than to use a meta refresh tag. Learn what a 301 redirect is and how to use them.

HTTP
Definition of the term HTTP.

Creating a Useful Page Not Found or 404 Error Page
Most Web servers have a way for developers to edit and maintain their 404 page. In many cases, you can even set up 404 pages for different areas of the Web site and to suit different purposes. But it's easy to create a 404 page that is basically useless.

HTTP/1.1 Specification
Learn more about HTTP direct from the source. The HTTP specification is maintained by the W3C.

HTTP Status Codes
The HTTP status codes are messages that the server returns when processing a request for a Web document. These messages include the standard 404 error message for a page not found through more obscure messages like 101 Switching protocols. This document explains the various error messages.

HTTP Pocket Reference by Clinton Wong
Understanding HTTP is key to understanding how your server works, and this book covers all you need