Paris is called after the Parisis, a Gaulish tribe who inhabited what is now the site of the city. Their capital, called Lutetia (Lutèce in French), is the ancestor of present-day Paris.
An arrondissement is a municipal district (close to a borough). Paris is made of 20 arrondissements all of which is known after its number (from the 1rs to the 20th). It is comparable to other big...