The internet (also known as the WWW, short for “World Wide Web”) is a vast array of interconnected computer systems, which originated from networks between educational facilities, and a similar scheme between the military.
It enables data to be transferred around the globe, across many different types of computer systems (the process is not proprietary to any particular type of computer), without you (generally) having to know anything about those different computer systems, or even be aware of the different systems, nor having to know about the nitty gritty technical details of how the data is transferred.
Another fundamental principle is distributing the data traffic over the entire network, rather than through a centralised system, so that the failure of any particular part of the network, doesn't completely destroy the functionality of the rest of the network (although it does tend to cripple it).
There are two major features of the internet that most people will be familiar with; e-mail, and webpages. This document will centre on webpages, but I will also briefly outline the e-mail system, as the two are commonly used together, and it helps to understand what's involved (in particular, I'm referring to webpages which have links, or forms, to send a message to an e-mail address).
Probably, the most common e-mail systems used by people, are; SMTP, POP3, and IMAP, which are abbreviations for Simple Mail Transfer Protocol (used for sending mail), and Post Office Protocol version three (used for retrieving mail), and Internet Mail Access Protocol (used for retrieving mail). All of which refer to the method used to transfer the mail.
They generally work using a client and server system, where you use an e-mail client program, for writing and reading your mail, and keeping copies of your mail (typically installed on a computer, though sometimes people use a service which operates through a webpage); the client interacts with a server system to send and retrieve your mail (typically provided by whatever service provider that you pay to get your internet access from). The server also usually acts as a temporary postbox, holding mail that's been sent to you, until you collect it (transferring the mail from the server, to your mail client). Likewise, when you send e-mail to someone, their server holds their mail, until they collect it. Though there are systems where the server acts as the storage point for all your mail, and you don't keep copies of them on the client (such as IMAP), which is very useful for people who use several different computers, and always need access to all of their stored mail, no matter which computer that they're currently using.
E-mail is a completely different system than webpages, although there are times when they two are used together (e.g. using a webpage “interface” to a mail system). It's as well to remember that not everybody has an e-mail program associated with their webbrowser, if they even have one (at all), and might not be able to easily use them in conjunction, before you create a webpage with that assumption. For instance, if you want people to be able to send you an e-mail through your webpage, you really should provide a method (e.g. a form), where they can do that without requiring anything extra. Conversely, if you want to e-mail a webpage link to people, then be sure to write the address completely (leave nothing out), so that it's far more likely that they can open the link from the message, without having to retype the address. It's also “standard” to bracket addresses written in plain text applications (like e-mail, and typed documents) with so-called “pointy brackets,” so that it doesn't get mixed up with any other surrounding characters.
Webpages would have to be the most popular aspect of the internet, allowing people to find out about all sorts of things, and publish their own works, (pretty much) free from censorship (which does mean that there's a lot of crackpots), and also without any authentication or checking of the material that they publish (which means that there's a lot of incorrect information).
Again, it's a client and server arrangement, where you use client software (a web browser), to view pages hosted on a web server. Those pages could be pre-written HTML files (the language used to write webpages), or the pages could be generated from other files (known as dynamically generated content), or a combination of both methods.
To have your own webpage (or website—more than just one page), you need to write the content, and host it somewhere. You can host webpages from your own computer, although that means that they're only accessible (to other people) while your computer is connected to the internet, and you have to know how to set up the server, and you should also take steps to protect your computer from malicious attacks. The easier solution is to have your pages hosted on another computer. Many internet service providers, will provide some webspace for their customers; and there are plenty of (cost) free hosts, as well as pay services (offering better features than a free service).
This guide will concentrate on writing the content, rather than on how to publish it.