Urban areas are characterized by high population density, with a large number of people living in a relatively small area.

Urbanization is the process by which people move from rural areas to urban areas.

Rural areas are characterized by low population density, with a small number of people living in a relatively large area.

Ruralization is the process by which people move from urban areas to rural areas.

Residential land use is the use of land for housing.

Agricultural land use is the use of land for farming.

The urban-rural fringe is the boundary between urban and rural areas.

The urban-rural fringe is characterized by mixed land use, with a combination of urban and rural land uses.

Urban sprawl is the process by which urban areas expand into rural areas.

Urban sprawl is characterized by leapfrog development, which is the development of new urban areas that are not contiguous with existing urban areas.

Peri-urbanization is the process by which rural areas become more urbanized.

Peri-urbanization is characterized by increased commuting, as people who live in rural areas commute to work in urban areas.

Suburbanization is the process by which suburbs become more urbanized.

Suburbanization is characterized by increased commuting, as people who live in suburbs commute to work in urban areas.

Deurbanization is the process by which urban areas decline.