South Jersey comprises the southern portion of the U.S. state of New Jersey located between the lower Delaware River and the Atlantic Ocean. The designation of South Jersey with a distinct toponym is a colloquialism rather than an administrative definition and reflects both geographical and perceived cultural differences from the northern part of the state with no official definition. Though definitions of South Jersey may vary, South Jersey is generally considered to be part of the Philadelphia metropolitan area, also known as the Delaware Valley, that surrounds and includes Philadelphia, the sixth largest metropolitan region in the nation with 6.096 million residents as of 2020.