A suburb is a residential area near a city or town but away from its center. The expression the suburbs refers to a group of these, or the residential outskirts of a city in general.

A suburb (also known as "suburban area") is a residential area near a city or town but away from its center. The expression the suburbs refers to a group of these, or the residential outskirts of a city in general.

My brother lives in a suburb of London.

She bought a new house in the suburbs of Los Angeles

Note that we use the preposition "in" with this noun; thus, we say "in the suburb/suburbs", not "on the suburb".

I used to live in the suburbs of Paris.

Be also aware that the plural form, suburbs, requires a verb in the plural, so we say "the suburbs are" (not "the suburbs is").

The suburbs of Berlin are fascinating.

What's the difference between suburbs and outskirts? While the term outskirts simply refers to the edges of a town or city, the suburbs are residential areas with borders or delimitations.