When you are developing a new Joomla website, you definitely need to know what joomla module positions your template consist of. For correct displaying each element has to be in it's Joomla module position. So to know how to show module positions in Joomla follow this simple steps:
Click Options button on the top right corner to enter the menu where you can display module positions in Joomla.
Choose Enable on Preview Module Positions row to show module positions in Joomla and click save.
Go to the frontend, type ?tp=1 at the end of your url and see that all Joomla module positions are displayed
Find more tips and tricks in Joomla tutorials section.