Also known as: 昭和, 昭和時代, 昭和初期
The Shouwa era is an Imperial period of Japanese history following Taishou spanning from 1926, December 25th, with the ascension to Emperor Shōwa, to 1989, January 7th, ending with his death. It was a long era spanning the majority of the 20th Century and generally divided into periods before and after the end of World War II and the subsequent occupation era.
The first half was defined by militaristic Imperial Japan's involvement in several wars, especially the two World Wars.
The second, post-war age is when restored democratic Japan became an economic power and the era ended with Japan in the midst of an economic bubble. When the Japanese say something is Shouwa-like and nostalgic, they usually mean something from the 1980s (Style), 1970s (Style), or possibly 1960s (Style).
It was succeeded by the Heisei era.