Once upon a time, a long time ago, there were a few computers connected together in a small distributed network. This was the 60s, a time of paranoia and space exploration, rock and roll and flower power, and the network was called ARPANET, and was an effort to provide a means of communication that would survive a nuclear attack. Over time, as the Cold War came to a conclusion, ARPANET evolved and grew, and plans began to emerge for its development.
(Rather than bore you will all the specifics of the emergence of the internet, if you are interested you can have a look at this [url=http://www.zakon.org/robert/internet/timeline/]detailed internet timeline[/url], although rumours abound that [url=http://www.c2000.com/fun/html.htm]the internet in fact began long, long before that[/url].)
Within a decade, email had emerged (Elizabeth II sending her first email in 1976), and in 1984 DNS (the system that controls domain names) was created. In 1990, as ARPANET finally shut down, the World's first commercial Internet Service Provider came online. The internet as we know it was born.
About this time, a great deal of data was already being thrown around the internet. Unfortunately, with a great number of different systems being used to view it, much of that data was in simple text form, sent by email. Out of the need for a better system for formatting data to show on all these different systems in the same way, HTML was finally born.
It was in 1989 that [url=http://www.w3.org/People/Berners-Lee/]Tim Berners-Lee[/url] invented the World Wide Web. In 1994, the same year the first version of Netscape's Navigator browser was released, he founded the W3C, the organisation now responsible for the standards used on the web, including HTML. The next year saw competition in the browser market, with the release of Internet Explorer, and the browser wars of the 90s were begun.
HTML was created out of the need to ensure that data was usable no matter what system you were running, and only by having a standard definition of the language could that be achieved. Tim Berners-Lee's logical markup provides an excellent, portable way to do that, using nothing more than any simple text editor.
HTML stands for HyperText Markup Language, and is designed to do just that - provide a way of laying out data so that no matter the system used to view that data, be it a PC, PDA or a screen reader, the data is still usable. It is a language invented to define the structure of web pages, to allow you to create headings to your web documents, emphasize those points that require it, allow you to show tables of data and offer readers related resources.
HTML uses a system of logical tags to indicate the purpose of each area of a document. Each tag, and there are many, can give an entirely different meaning to any different part of a document. For example, the text "logical tags" above is enclosed in a pair of tags to indicate emphasis, like so: <em>logical tags</em> (the first tag in HTML indicating the start of the emphasized text, the second the end).
The chances are that, if you are using a current browser, the above text looked italic to you (if you were using a screen reader, that text may have been spoken in a slightly louder tone, or at a different pitch). HTML has been designed to only indicate that there is emphasis on those words, nothing more, and the form that emphasis takes can depend on the page designer or the tool used to view the page.
This is where HTML becomes slightly tricky. HTML is not a presentation language. That is to say, HTML is not written to provide a method to lay out a web page, or to specify colours, or spacing, or fonts. Neither, though, is it a programming language, being unable to process data or do any calculations.
However, in the mid to late 1990s, there was no other realistic way to achieve the effects that were required of the web at the time than to use HTML. Thus, the web design community started to work around problems they faced with a lack of a well-implemented method for achieving the look of pages that they required, and started to use workarounds and hacks.
Before long, people were using nested tables to lay out pages, and the look of text was being specified using hundreds of font tags spread throughout sites. Updating a web site became a nightmare, and designs had to be tested in a selection of browsers to ensure that all of the little quirks that those browsers had were catered to. Cross-browser compatibility was a phrase heard far too often in the 90s.
Fortunately, this phase is coming to an end. CSS (cascading style sheets) are being more widely used, thanks to better implementation of web standards by the browser manufacturers, allowing designers to use HTML for what it was intended - indicating purpose rather than defining style.
Designers are able to now separate the structure of their web pages from the presentation, making for a faster, more useful, more accessible internet. If you are considering learning HTML, now is a good time to start.