Using themes (really beginner question)

Im trying to figure out how to use themes. I select the different themes but I cant see any visual differences?I go to settings and change between the build in themes and then I go back to see if anything changed. Obviously its not the way - but how to use it then?


The themes are just basically a CSS setup. Do you have anything on a page for it to change? If not then the only change you may see will be a background color and nothing else. Add some elements to your page and then you should see some changes if you change the theme.