Edge city is an American term for a relatively new concentration of business, shopping and entertainment outside a traditional urban area, in what had recently been a residential suburb or semi-rural community. The term was popularized in a 1991 book of that title by American writer Joel Garreau, who invented it while working as a reporter for the Washington Post. Garreau argues that the edge city has become the standard form of urban growth worldwide, representing a 20th-century urban form, as distinct from the 19th-century version of the central downtown.