HTML5 is a core technology markup language of the Internet that is
used for presenting and structuring content for the World Wide Web. This
is the complete fifth revision of the World Wide Web Consortiums
(W3C) HTML standard.
HTML 5 mainly aims at improving the language with support for the
latest multimedia keeping it consistently understood by computers and
devices (parsers, web browsers etc.) and easily readable by humans.
HTML5 is a response to the fact that the XHTML and HTML in common use
on the World Wide Web are a mixture of features that have been
introduced by various specifications along with the ones introduced by
software products like web browsers and the ones established by common
HTML5 introduces attributes and elements which reflect typical usage
on modern websites. A number of them are semantic replacements for
common uses of inline (<span>) elements and generic block
(<div>), such as <nav> (website navigation block),
<footer> or <audio> and <video> instead of
<object>. Some deprecated elements from HTML 4.01 including purely
presentational elements like <font> and <center> have been
dropped, whose effects have been succeeded by the more capable Cascading
Style Sheets. There has also been a renewed emphasis on the DOM
HTML5 specifies scripting application programming interfaces (APIs)
facto features have been documented and existing DOM (document object
model) interfaces have been extended. Also, new APIs are there, such as:
Timed media playback, Offline Web Applications, Drag-and-drop,
Cross-document messaging, Browser history management, MIME type and
protocol handler registration, Microdata, Document editing, the canvas
element for immediate mode 2D drawing.
HTML5 has been designed so that old browsers may safely ignore new
HTML5 constructs. The HTML5 specification provides detailed rules for
parsing and lexing, with the intention that different compliant browsers
produce the same result for an incorrect syntax.