You'll hear and see the word bitte a lot in German. It can have several meanings, depending on the situation, but it's always polite.

Bitte can mean please

Können Sie mir helfen, bitte?                                 Can you help me, please?
Ein Bier, bitte.                                                         A beer, please.

Bitte sehr is used when handing something over.

Bitte sehr, Ihr Bier.                                                  Here you are, your beer.

Bitte schön is used in reply to Danke

Danke                                                                     Thank you.
Bitte schön                                                             You're welcome.