What is a module and how do you position it?
Every template comes pre-equipped with a layout. Within this blueprint, you have a number of options available for placing your content.
When designing a website page, you'll be setting up two types of content: the primary and secondary. In the Joomla content management system, the primary content is usually placed within the "Article" and the secondary content would be placed within a module. The menu, logo, search box, login area, footer, and so on. All of this secondary content in placed into what is known as a "Module". To discover the template module positions that are available, you can look at this map or add the ?tp=1 to the end of your URL (http://www.yoursite.com?tp=1).
In the newest version of Joomla, you can turn the module finder command on and off. If nothing happens when you add the little command to the end of your URL, then go to Extensions>Template Manager and click on Options. In that pop-up you're given the option to "Enable" the module position finder. Once enabled, click save and close.