Joomla is an award-winning CMS (content management system). It's ease-of-use and extensibility, have made Joomla the most popular website software available. 

What's a content management system (CMS)?

A CMS stores and keeps track of every piece of content on your website. Content can be  text, photos, music, video, documents etc. One advantage of using a CMS is that it requires almost no technical skill or knowledge to manage. Since the CMS manages all your content, you don't have to.