The Federal Government defines environmental justice as the official government policy that all American citizens deserve to be treated equally with regard to the passage and application of environmental laws— regardless of where they live. This policy emerged out of fear that environmental issues like pollution were disproportionately affecting lower-income communities.

The term “blockbusting” is used to refer to a common practice in the real estate business in the twentieth century (in some places it persists to this day). It involves a realtor trying to intimidate a white property owner into selling inner city property and moving to the suburbs. The realtor convinces the white property owner that the neighborhood is “in decline” due to the large numbers of minorities moving into the area. This process accelerated the rate of suburbanization in the twentieth century. Due to its obviously racist implications and manipulative nature “blockbusting” has long been controversial.

By definition, a squatter settlement is a collection of buildings aimed to provide housing and shelter for poor people in a city. The people who live in squatter settlements do not have legal rights to the land upon which they are built; therefore, they are living there illegally. Squatter settlements are a housing alternative when affordable housing is otherwise hard to come by in a city. 

“Counter urbanization” refers to the process by which a significant portion of the population of an urban center starts to migrate away from the city to live in suburbs or rural areas. This of course cannot happen without large-scale urbanization and the acquisition of wealth so it is most likely to occur in highly developed regions.

The term “yuppie” is a reasonably modern term that is derived from “young professional.” It is a term usually applied to young, reasonably affluent people who move from the suburbs into inner city areas in search of close proximity to work and entertainment.

An “exurbanite” is someone who has left the inner city to live in the suburbs. It may also describe people who used to live in the city in general who have moved to rural areas. Someone who works in the city and lives in the suburbs is called a "suburbanite."

Gentrification describes urban renewal that leads to the displacement of the occupying demographic. It is commonly associated with rising property values in previously low-income urban areas, which may force current residents to move away.

The term “gentrification” is applied fairly liberally in contemporary American geographical language. It primarily refers to the process by which an urban or suburban neighborhood transitions from housing people of mostly low-income status to housing middle class families. In some expressions it can have racist connotations.

The term “gentrification” is used to describe the process by which affluent, middle-class families return to inner city neighborhoods from the suburbs. Although generally considered a positive trend because it contributes to urban revitalization, it has some negative consequences. One of these is that lower-income families can no longer afford the rent or cost of living in the neighborhood and are forced to relocate.

All of the statements above would be supported by critics of gentrification, except the statement about historic preservation. When gentrification happens, an area that was previously deteriorated gets renovated, and any historical locations within that area get preserved.