When speaking about large heavily populated areas, the term "conurbation" is often used. However, there are several synonyms that can be used interchangeably with the term. Urban agglomeration, metropolitan area, megalopolis, and urban conglomeration all refer to a densely populated area where cities and towns merge into a single conjoined entity. The term urban area is also often used interchangeably with conurbation, referring to a densely populated residential or commercial region. These synonyms are frequently used by urban planners, geographers, and other professionals involved in identifying and addressing issues in large urban areas, such as transportation, housing, and infrastructure development.