Joomla is a free and open source content management framework (CMF) for publishing content on the World Wide Web and intranets. It includes features such as page caching, RSS feeds, printable versions of pages, news flashes, blogs, polls, search, and support for language internationalization.
Over 9,200 free and commercial extensions are available from the official Joomla! Extension Directory, and more are available from other sources. It is estimated to be the second most used CMS on the Internet after WordPress. Joomla won the Packt Publishing Open Source Content Management System Award in 2006, 2007, and 2011.
You can think of a Joomla! website as bringing together three elements:
your content, which is mainly stored in a database;
your template, which controls the design and presentation of your content (such as fonts, colors and layout);
Joomla! which is the software that bring the content and the template together to produce webpages.