Suburb, community that lies on the outskirts of a city. Suburbs can be residential or industrial, or a combination of both. A city may have any number of suburbs surrounding it. A suburb may be self-governing, or be governed by the city near it, or by the county in which it lies. Suburbs began in the late 19th century when railroad expansion enabled people to work in a city and commute to homes outside of it. Suburbs blossomed further with the development of automobiles and roads. Now, more people live in suburbs than in cities.