What on earth is? HTML

In an industry awash with acronyms, HTML is the one bandied about more than most. It stands for Hyper Text Markup Language and is the lifeblood of the web.

Put simply, HTML provides a website's stage directions. Every last element of the pretty pages that appear in your web browser are described in intricate detail using the multifarious commands and codes that make up HTML.

With that in mind, it's not surprising that HTML is synonymous with the internet. Every minute of every day, the world's communication networks are humming with HTML as it delivers websites and stylised emails to millions of internet users.

HTML's creator, however, never envisioned such widespread use of his system. In March 1989, European Centre for Nuclear Research (Cern) fellow Tim Berners-Lee circulated a document among management and colleagues.

His Information Management: A Proposal paper described a global network of linked research reports. Regular staff turnover at Cern meant that important information was being lost in the organisation's vast, unstructured computer databases.

Berners-Lee proposed permanently tethering documents together using a technique called hypertext. As research papers were prepared, authors would mark up key words and phrases and use them as pointers to other relevant research material.

Over time, mused Berners-Lee, the network would grow to include every document produced by Cern - a mesh of information linked together using the newly invented HyperText Markup Language.

As the idea took hold, the Oxford graduate began work on a system to allow people to easily negotiate the information stored in Cern's growing hypertext-linked databases. In December 1990, he unveiled his first hypertext browser which he called WorldWideWeb.

The browser worked only on high-end computers but the technological monopoly was short lived. Within months, programmers produced HTML browsers for numerous computing platforms and the wheels of the web were set in motion.

The basics

HTML is nothing more than a series of codes known as tags which turn plain text into the multicoloured, multimedia extravaganza that is a typical web page. The tags are many and varied but, in principle, they're very simple - one tag turns on an effect, another turns it off.

For example, to make a piece of text appear in bold, it is prefixed with the tag 'b' (tags are enclosed in angled brackets) and ended with '/b'. Similarly, the 'i' tag specifies italics, the 'font' tag specifies the text's font and so on.

HTML also extends to include other elements in a page, such as images. The 'img src' tag specifies the filename of an image and, if need be, the height and width at which it is to be displayed.

The most fundamental aspect of a web page is the hyperlink - text or graphics that when clicked open a new page. Hyperlinks are specified with the 'a href' tag.

Why you need to know about it

Only web page designers need be concerned with the intricacies of HTML but an understanding of hyperlinks can aid web surfing.

Web pages are prefixed with http:// (or hypertext transfer protocol). Modern web browsers append this to any web address you tap in, so it's pretty much transparent.

Put the mouse pointer over a hyperlink and the location and protocol of the target document is displayed in the bottom left-hand corner of the web browser window. If it begins with anything other than http://, it's not a link to a website. A mailto: prefixed link will bring up an email window.

Similarly, the tail end of the target link is worth noting. Locations ending in .htm or .html are generally straightforward HTML pages and should download quickly. Other extensions such as .asp, .shtml and .swf may indicate links to complicated media or websites heavy with graphical menus.

The science

If there is a science behind HTML, it is one of logic. A cryptanalyst poring over HTML code would soon figure out that simple 'on' and 'off' instructions form the basis of the display parameters, with short codes denoting command specifics.

Creating a web page using HTML requires nothing more than a text editor and many web designers rely on Microsoft's Notepad. While simple in principle, HTML can soon become convoluted - try selecting the Source option from Internet Explorer's View menu when looking at a page to see just how complicated most pages are.

Few people will try their hands at raw HTML these days; most rely on applications that create the HTML from pages created in a WYSIWYG editor.

Since a web page is in essence a page of text, it's the job of the browser to translate it into a web page proper. The browser 'parses' the list of instructions, stripping out the tags and using them to format the remaining text. It also plucks images from the web server according to HTML code and displays them in the appropriate place.

JARGONBUSTER

Font This is the measurement typographers use to describe the size of text.

WYSIWYG What You See Is What You Get. Signifies that the on-screen image of your page is the same as the printed output or published web pages.

Server A shared, central computer that is linked, directly or indirectly, to other remote computers and can be accessed by them. The internet consists of tens of thousands of servers.