This document discusses concepts related to metropolitan and suburban areas. It begins by defining Metropolitan Statistical Areas (MSAs) as urban areas with 50,000 or more people that represent cities, and Microropolitan Statistical Areas (M-PSAs) as smaller areas with 10,000-50,000 people that represent suburban areas beyond cities. It then discusses factors related to suburban growth and sprawl over the 20th century, as well as issues of social class, race, poverty, and politics in cities and suburbs.