HTML
Contrary to what most people believe, HyperText Markup Language (HTML) is not a programming language like BASIC or COBOL; rather it can be described as a markup language, or a page-description language. The function of HTML is to facilitate you to create pages of text, images and other elements, that can be viewed using a browser. An HTML file is simply a set of instructions for creating a page on a computer screen. The makers of the application software can have their products interpret those instructions in whatever way they choose.
The text can be designed with various types of formatting, similar to that created with a word processor. However, you can also include hyperlinks, which are multifaceted in their utility.
There are hundreds of millions of Web users, using the whole gamut of computer equipment to connect to the Web such as Windows, Mac, Unix, desktops, laptops and TVs There are also many different types of browser programs that display Web pages in slightly different ways. In fact, the two major browser makers, Netscape and Microsoft, have intentionally increased, rather than reduced, the differences between their browsers, so that pages designed for one browser do not gel with the other. Moreover, not only have the browsers each been upgraded to new versions several times, the language of HTML itself has been revised as well, having presently reached level 4.0
This complexity caused by disparate operating systems, varied browser versions and different HTML levels, means that designing for the Web is more difficult than traditional media. As a Web publisher, you can never be sure how your material will appear on different systems. You must also think about the intended audience for your site, and take their technological limitations into account when designing your pages. For example, the latest techniques may not work on older or lower powered systems. Certain graphics or web pages may not load properly and may lead to a crash!