there are three different versions of Joomla: Joomla 1.5, Joomla 2.5, and Joomla 3.x. Each version of Joomla caters to different requirements and offers a range of unique features. Joomla 1.5 offers a simple interface for website development, Joomla 2.5 has enhanced security and improved user experience, whereas Joomla 3.x is the latest version that provides a better responsive design and improved Bootstrap support.