Hi Caitlin! Polarizing filters have several uses; they enhance color a bit, and they also can cut down on reflections. I usually use a polarizing filter when shooting waterfalls, or any other body of water that I don’t want reflection on. You can also use a polarizer when there is a blue sky with white clouds, as it will enhance the blue, and make the clouds stand out more.
That said, I don’t use filters that often, so I’m sure there are many other applications!