While designing your website, you mostly need to know which module positions your template contains. To see the module positions and their names in frontend of your template do the following:
Step 1: Go to your Joomla administrator
Step 2: Go to your "Extensions" and select "Template Manager"
Step 3: The page should look like the picture below and then Click "Option"
Step 4: In the Preview Module Positions. Click "Enabled"
Step 5: Click the "Save button
Step 6: Go to your frontend site and add the following suffix to your URL: tp=1
Now the module positions and their names are displayed over the template in frontend. See the picture below