Industrial Revolution: A period of rapid industrialization characterized by technological advancements that transformed economies from primarily agrarian-based to manufacturing-based. The Industrial Revolution greatly influenced demographic shifts including urbanization and changes in birth rates.
World War II: A global conflict fought between 1939 and 1945, which had profound effects on many countries including Japan. WWII led to social and economic disruptions that impacted Japan's demographic structure.
Post-War Reconstruction: Refers to efforts undertaken after World War II to rebuild and redevelop societies affected by the war. Post-war reconstruction efforts in Japan influenced population trends and contributed to its aging population.