introduction to HTML5

HTML5 is the latest iteration
of HTML, Hypertext Markup Language, a language for structuring and presenting content for the World
Wide Web. HTML elements are the building blocks of web pages. At the time of writing, the HTML5
specification is still in development, but a number of features are considered stable and ready to use, such
as the canvas element. HTML5 improves on HTML4, which was standardized in 1997, by adding new
elements and support for multimedia content, such as audio and video. Because these new, semantically
meaningful elements expose properties and controls that are accessible in the document, you can
manipulate them programmatically using JavaScript, giving you a powerful way to control and create
media.
HTML5 is a collection of individual features. When assessing a particular browser’s HTML5 support, this is
not an all-or-nothing classification; rather, you test if a browser supports a specific feature of the defined
specification. Different browsers have different support for different features. This can make it difficult to
target individual HTML5 elements without knowing how a user will view the document. As browsers
continue to improve, cross-platform feature detection becomes less of a concern, but for now, you should
always test the user's web browser for the HTML5 features you target and provide a backup solution if it
fails—even if it’s just a politely worded message instructing your user to upgrade his browser.