A great feature of Joomla is the Module Manager, which allows you to insert various functions into your website. Perhaps you want to include a search bar, or a latest news updates box, or a menu contained within your websites side bar. The module manager is where all this action begins.
Joomla already has a whole lot of great default modules you can begin using straight away, and there are also literally thousands of other modules and plugins you can download from the Joomla Extensions Directory that have been submitted by many Joomla users around the world.
In earlier version of Joomla, identifying module positions in a template was a relatively easy task. Using the command ?tp=1 in your URL displayed an overlay on your websites template revealing each module position. This is very handy if you want to identify the placement of a particular module position, and can still be achieved in Joomla 1.6.