Tags are used in HTML5 to place and organize content at a level
that is descriptive. This does not mean that the page will look
good. Presentation of content on the page is controlled using
Cascading Style Sheets Level 3, or CSS3, in HTML5.
Using CSS3 to describe how your page should look, however,
is not new. The technology was first introduced in 1997 and is
now, in HTML5, in its third major release, named CSS3. The good
news is that all CSS1 and CSS2 standards are fully supported by
For this book you will use CSS to format web pages. There are
good reasons why you want to do this. The first, and most important,
is that CSS is a tool that allows you to easily apply page
styling techniques to a whole web site from a single, text-based
document. This means you can quickly change the visual layout
of a page, selection of pages, or the entire site.