This document is intended to help Linux and Internet users who are learning by doing. While this is a great way to acquire skills, sometimes it leaves peculiar gaps in one's knowledge of the basics -- gaps which can make it hard to think creatively or troubleshoot effectively, from lack of a clear mental model of what is really going on.
I'll try to describe in clear, simple language how it all works. The presentation will be tuned for people using Unix or Linux on PC-class hardware. Nevertheless I'll usually refer simply to `Unix' here, as most of what I will describe is constant across platforms and across Unix variants.
I'm going to assume you're using an Intel PC. The details differ slightly if you're running an Alpha or PowerPC or some other Unix box, but the basic concepts are the same.
I won't repeat things, so you'll have to pay attention, but that also means you'll learn from every word you read. It's a good idea to just skim when you first read this; you should come back and reread it a few times after you've digested what you have learned.
This is an evolving document. I intend to keep adding sections in response to user feedback, so you should come back and review it periodically.
If you're reading this in order to learn how to hack, you should also read the How To Become A Hacker FAQ. It has links to some other useful resources.
New versions of the Unix and Internet Fundamentals HOWTO will be periodically posted to comp.os.linux.help and news:comp.os.linux.announce and news.answers. They will also be uploaded to various Linux WWW and FTP sites, including the LDP home page.
You can view the latest version of this on the World Wide Web via the URL http://sunsite.unc.edu/LDP/HOWTO/Fundamentals-HOWTO.html.
If you have questions or comments about this document, please feel free to mail Eric S. Raymond, at esr@thyrsus.com. I welcome any suggestions or criticisms. I especially welcome hyperlinks to more detailed explanations of individual concepts. If you find a mistake with this document, please let me know so I can correct it in the next version. Thanks.