Short answers, pulled from the story.
The name is short for Arts Decoratifs, taken from the International Exhibition of Modern Decorative and Industrial Arts held in Paris in 1925. The actual printed term Art deco did not appear until 1966, in the title of an exhibition at the Museum of Decorative Arts in Paris. Historian Bevis Hillier popularized it as an academic label with his 1968 book Art Deco of the 20s and 30s.
Miami Beach, Florida has the largest concentration of Art Deco architecture in the world, including a cluster of hotels built after World War II.
It was the International Exhibition of Modern Decorative and Industrial Arts, held from April to October 1925 on a 55-acre site running from the Grand Palais to Les Invalides. It attracted 15,000 exhibitors from twenty countries and was visited by sixteen million people. The exposition required all exhibited work to be modern, with no historical styles allowed.
Two forces drove its decline. The French Union of Modern Artists, founded in 1929, attacked Art Deco as a style made only for the wealthy and promoted modernism and mass production instead. The Great Depression, starting in 1929, drastically reduced the wealthy clientele who could afford Art Deco's expensive materials and craftsmanship. After World War II, the International Style replaced it as the dominant architectural language.
Art Deco introduced chrome plating, stainless steel, and plastic into decorative design, alongside new uses for aluminium and plate glass in architecture. It also made early use of bakelite, an early plastic that could be moulded into radios, telephones, and other appliances.
Auguste Perret and Henri Sauvage were the leading Art Deco architects in Paris in the 1920s. Perret built the Theatre des Champs-Elysees between 1910 and 1913, the first landmark Art Deco building in Paris. In the United States, William Van Alen designed the Chrysler Building, completed in 1930, and William F. Lamb designed the Empire State Building, completed in 1931.