Bxslider showing duplicate bxviewport

In my html i have a code like below

but when the html renders on the browser i can see some duplicate bxviewport and bxslider as below and its distorting the ui as you can see from the screen shot on the left

resolved this by removing the >templatename in the body. Can some one pls help me understand on what scenarios, >templatename is used in the body? I can see even without using this the page renders with just the template definition.