Area source refers to a stationary source of pollution that has a distinct geographic location. Synonyms for this term can include localized source, point source or ground-level source. A localized source refers to a specific location where pollutants are being released, such as a factory or industrial plant. A point source, on the other hand, denotes a single discharge outlet where pollutants are being emitted, such as a smokestack. Finally, a ground-level source refers to pollution that is released at close proximity to the ground, such as vehicular emissions. It is important to distinguish between these terms to identify the specific type and location of pollution being released into the environment.