Polaris is a term used for United’s international business class. It includes the Polaris Lounges, on board amentity such as gel pillow, slippers, pajamas on selective routes and supposed to be better in-flight meals.

There is really no Polaris on domestic routes including PS.

The new seat is also not officially labeled Polaris seat. It is just simplly a new business class seat in a newly designed and configured layout/cabin. All pieces collectively called Polaris Business cabin.