Art Deco is a style that was very popular in the 1920s and 1930s. It is an antique style which characteristics include geometric shapes and bright colors.
It was very different than the prior turn of the century Art Nouveau period. Instead of free-flowing, natural Art Nouveau designs, the Deco style was the opposite. It was decorated with straight lines and broadly defined curves.
The Art Deco design is often used in jewelry, furniture, paintings, lighting, and much more. Many people design homes and buildings in this style. Some people love this style, while others may feel it is just too geometric. It is simply a matter of taste. However, people that decorate in the popular mid-century modern design style may have a few deco pieces mixed in.