The term Beaux-Arts is French for Fine Arts and has come to define the architecture that emerged roughly between 1880 and 1930. The advent of Beaux-Arts coincided with similar movements of the time, such as the Progressive Era, the City Beautiful Movement, the Edwardian Era, and the Belle Epoque. Though Beaux-Arts may often be recognized as an architectural style imitating the classic forms of the Ancient and Renaissance worlds, many would argue that it is more of a manner of architectural execution and finish. (Due to this confusion over nomenclature, the word style will be placed in quotations.)
One often hears the style dubbed the Ecole des Beaux-Arts. This denotation actually refers to a school in Paris called the Ecole Nationale Supérieure Des Beaux-Arts. This school, formed in 1819, was nothing more than a government-run school of the arts. However, its significance reached far beyond the walls of the school, as the architects trained there would be responsible for the creation of an architectural style/era/manner of execution named after the school.