The city has a unique status in Brazil, as it is an administrative division rather than a legal municipality like other cities in Brazil. Although Brasília is used as a synonym for the Federal District through synecdoche, the Federal District is composed of 31 administrative regions, only one of which is the area of the originally planned city, also called ''Plano Piloto''. The rest of the Federal District is considered by IBGE to make up Brasília's metro area.