What is HTML5 ???

New APIs

In addition to specifying markup, HTML5 specifies scripting application programming interfaces (APIs) that can be used with JavaScript. Existing document object model (DOM) interfaces are extended and de facto features documented. There are also new APIs, such as:

HTML5 related APIs. HTML5 & CSS3 Quick Reference by Sergey Mavrody .
The canvas element for immediate mode 2D drawing. See Canvas 2D API Specification 1.0 specification
Timed media playback
Offline Web Applications
Document editing
Drag-and-drop
Cross-document messaging
Browser history management
MIME type and protocol handler registration
Microdata
Web Storage, a key-value pair storage framework that provides behaviour similar to Cookies but with larger storage capacity and improved API.
Not all of the above technologies are included in the W3C HTML5 specification, though they are in the WHATWG HTML specification.Some related technologies, which are not part of either the W3C HTML5 or the WHATWG HTML specification, are as follows. The W3C publishes specifications for these separately:
Geolocation
Web SQL Database, a local SQL Database (no longer maintained).
The Indexed Database API, an indexed hierarchical key-value store (formerly WebSimpleDB).
File API, Handle file uploads and file manipulation.
Directories and System. This API is intended to satisfy client-side-storage use cases not well served by databases.
File Writer. An API for writing to files from web applications.

HTML5 alone cannot provide animation within web pages. Either JavaScript or CSS3 is necessary for animating HTML elements. Animation is also possible using JavaScript and HTML 4[not in citation given], and within SVG elements through SMIL, although browser support of the latter remains uneven as of 2011.