Introduction

When the World Wide Web was first invented by Tim Berners-Lee, simply having a means to create hypertext links to other documents (including ones on remote computers), and to combine text and images using basic formatting, were revolutionary concepts that we take for granted today.

But slowly web developers started getting used to the initial 20 elements provided by HTML (Hypertext Markup Language) 1, and began adding more and more features in each new specification of the language. Luckily, though, the people driving this development realized early on that if these extensions to the language were not handled sensibly, they could end up as an unwieldy, tangled web of tags. Thus, it was decided to include cascading style sheets (CSS) within the specification so the content of web pages could be completely separate from the design and layout.