The term 'Style of the '20s and '30s' refers to two distinct art movements, Deco and Art Deco. Deco is a style of art and architecture that emerged in the 1920s and 1930s, characterized by geometric shapes, bright colors, and bold designs. Art Deco is an extension of the Deco movement, which was popularized in the 1930s and 1940s. It is characterized by more ornate designs, often featuring curved lines, intricate patterns, and luxurious materials. Both styles are still popular today, and have been used in many modern designs.