What seems to the focus of The Star Spangled Banner?

As its name might suggest, the Star Spangled Banner focuses on the U. S. flag, which could be called a star spangled banner as it has stars (of extra significance because there were 13 stars representing the 13 colonies fighting in the war) and flags are a type of banner. The song is about how the American flag's still waving as the sun comes up, how Americans made it through that hard night of battle.