HTML and CSS Reference
main content, and footer areas would have a minimum of three <div> tags. HTML5, by contrast,
offers specific <header> and <footer> tags, as well as ones for content such as <article> and
<summary> . HTML5 contains numerous other structural elements for handling figures, forms, and
navigation as well. Most of these have not yet been implemented by current browsers as of this
The other major difference — and one that has gotten a lot of attention recently with the release of
the Apple iPad — is built-in media support. In HTML4 and earlier, if you wanted to show an anima-
tion or play a video, you needed to use a browser plug-in, such as the Adobe Flash Player. HTML5
includes native support for playing video and audio through the <video> and <audio> tags, respec-
tively, as well as static and animated vector graphics via the <canvas> tag. A few browsers on the
cutting-edge, including the latest versions of Firefox and Google Chrome, have begun to support one
or more of these elements, as shown by the video playing in Safari 4.0.5 in Figure 1-2.
To find out more details about the newest elements of HTML5, see Section 10
later in this topic.
In this Try It you learn how to review the HTML source code for any given web page.
You will need an Internet connection and a web browser, such as Internet Explorer, Firefox, or Safari.
Open your favorite browser.