Is just a way to tag parts of a
document so that Web browsers
can deal with them intelligently.
HTML5 is both a single
specification and a whole set
of technologies.
HTML5 is most often thought of broadly
to include new versions of the markup
language itself and its associated standard
for accessing and manipulating HTML
documents
The Document Object Model; Cascading Style
Sheets (CSS), a language to define the presentation
and appearance of an HTML document; and the
JavaScript scripting language. The term is often
used even more broadly to include specific
application programming interfaces (APIs), such as
those that enable new browser-based graphics,
geolocation, local storage, and video capabilities.
Similarly, CSS3, the newly updated
presentation language, allows a developer to
produce certain looks natively in the browser,
without constructing them externally