Final answer:
Edge cities are commercial hubs located on the periphery of older urban areas, characterized by a dense mix of businesses, retail, and office spaces, and have become key centers of employment and economic activity.
Step-by-step explanation:
The sprawling, middle-class, auto-dependent centers typically located at the intersection of major highways at the fringe of an older urban area are referred to as edge cities. An edge city is characterized by a high concentration of business establishments, including shopping malls, office complexes, high-rise apartment buildings, and industrial parks.
These areas, sometimes called suburban downtowns, have emerged as significant new commercial hubs, often surpassing the central business district (CBD) as centers of employment and economic activity. Edge cities have played a key role in urban sprawl and are a product of the decentralization of cities due to the increase in automobile ownership and the corresponding demand for accessible suburban living.