Edge city is a term that originated in the United States for a concentration of business, shopping, and entertainment outside a traditional downtown or central business district, in what had previously been a suburban residential or rural area. The term was popularized by the 1991 book Edge City: Life on the New Frontier by Joel Garreau, who established its current meaning 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 unlike that of the 19th-century central downtown. Other terms for these areas include suburban activity centers, megacenters, and suburban business districts. These districts have now developed in many countries.