"Jumla" is the Swahili word for "all together" and was the inspiration for the name Joomla!. The Joomla! project is one of the biggest content management systems worldwide, backed by a global community.
Joomla! 2.5 is the sucessor of Joomla! 1.5. It is a long term release and represents the state of the art for the Joomla! project from January 2012 to September 2013. It lets you create unique websites in your own language.
Even if you are not a specialist :-)