The term "arrondissement" refers to a municipal district. In Paris, there are 20 arrondissements which are grouped in the form of a clockwise spiral. The 1st arrondissement is found in the middle of the city on the right bank of the Seine and includes the Louvre.

If you know the postal code of an address in Paris, you know the arrondissement... the final two digits correspond to the arrondissement. An address with a postal code of 75002 is in the 2nd arrondissement; a postal code of 75018 is in the 18th.

"Right Bank" and "Left Bank" refer to the banks of the Seine, which flows through Paris from east to west. Looking down-river, the Left Bank is on your left (south), and the Right on your right (north).