What is Gentrification?

Legal Definition
Gentrification is a process of renovation and revival of deteriorated urban neighborhoods by means of influx of more affluent residents, which results in increased property values and the displacing of lower-income families and small businesses. This is a common and controversial topic in urban planning. Gentrification may be viewed as "correction" of blockbusting and urban flight as many gentrified neighborhoods of the present were once affluent neighborhoods of the past.

Gentrification is typically the result of increased interest in a certain environment. Early "gentrifiers" may belong to low-income artists or boheme communities, which increase the attractiveness and flair of a certain quarter. Further steps are increased investments in a community and the related infrastructure by real estate development businesses, local government, or community activists and resulting economic development, increased attraction of business and lower crime rates. In addition to these potential benefits, gentrification can lead to population migration.

In a community undergoing gentrification, the average income increases. Poorer pre-gentrification residents who are unable to pay increased rents or property taxes may find it necessary to relocate.
-- Wikipedia
Legal Definition
The evolution of an area due to an influx of wealthier residents and an influx of their wealth into an area. Lower-income residents begin to sell, profiting from wealthier inhabitants moving into the neighborhood, changing the perspectives. Typically begins an urban renewal process, cleaning up the town, increased rent, taxes, and other items, as expectations rise. Previous residents unable to afford living in the neighborhood view this gentrification in a negative context. Yet, decreased crime rates and increased economic activity are some of many good changes that historically accompanies gentrification.