HTML5 defines the fifth major revision of the core language of the World Wide Web, HTML. "HTML5 differences from HTML4" describes the differences between HTML4 and HTML5 and provides some of the rationale for the changes. This document may not provide accurate information as the HTML5 specification is still actively in development.
HTML 5 is the next revision of the Hypertext Markup Language (HTML), the standard programming language for describing the contents and appearance of Web pages. HTML, which stands for HyperText Markup Language, is the predominant markup language for web pages. A markup language is a set of markup tags, and HTML uses markup tags to describe web pages.
HTML5 is a W3C specification that defines the fifth major revision of the Hypertext Markup Language (HTML). One of the major changes in HTML5 is in respect to how HTML addresses Web applications. Other new features in HTML5 include specific functions for embedding graphics, audio, video, and interactive documents.
HTML has been in continuous evolution since it was introduced to the Internet in the early 1990s. Some features were introduced in specifications; others were introduced in software releases. In some respects, implementations and author practices have converged with each other and with specifications and standards, but in other ways, they continue to diverge.
In all probability you know about the latest blogging tool HTML5, some have embraced it, while others are sceptical over its use. The dynamic behaviour of the Internet makes latest technology obsolete tomorrow. However, we cannot ignore the fact that yesterday’s technology is the building block of present and future technologies. For instance, when developing a new stable scripting language we usually turn to the native code, as it tends to remain unchanged for a long time.
DOCTYPE is a simpler command carried over from HTML, and is embedded in the source w3.org. It is a command compatible with older versions of Internet browser. Meanwhile, if we use <!DOCTYPE html5> it triggers Quirks Mode in IE6, that correlates to backward compatibility, hence <!DOCTYPE html>.
New Elements Introduced:
The W3C community has listened sincerely to suggestions and perceived a future Internet architecture, where abundance of features is essential for its sustainability and growth. HTML5 includes basic and advanced structural elements to offer a rich browsing experience. For instance, with a powerful API, it allows programmers to create more user-friendly applications, and reducing the dependency on Flash for saving data and intense animation.
<header> contains introductory information to a page or section. It can include branding information to an entire table of contents.
<nav> retains the links to other pages or other sections of the same page. Primary navigation links are to be contained in this element, only.
<section> represents a generic document or application. It behaves in the similar manner as <div>, separating a portion of the document.
<article> indicates an independent portion of a page like blog post and forum entry.
<aside> describes the content associated with main area of the document. It can be used to pull quotes, posts and tags.
<footer> is used for marking the ending of each page. It can also be used for each section on the same page.
At first glance, these new elements seem to replace common DIV Ids. However, further analysis reveals that these behave like classes and normal HTML elements, which can be repeatedly used for retaining semantic structures.
HTML 4.01 and XHTML 1.0 have small syntax differences that can invalidate code. Bearing this in mind, HTML5 has built-in “slack” to make the transition easier.