There have been two World Wars in history. These were large-scale global conflicts that involved many of the world’s nations.
World War I (1914-1918) was the first global conflict. It began after the assassination of Archduke Franz Ferdinand of Austria-Hungary and involved the Allied Powers (including France, Russia, and the United Kingdom) against the Central Powers (including Germany, Austria-Hungary, and the Ottoman Empire). The war ended with the Treaty of Versailles in 1919.
World War II (1939-1945) was the second global conflict. It started when Germany, led by Adolf Hitler, invaded Poland. This war involved the Allies (including the United States, the Soviet Union, and the United Kingdom) against the Axis Powers (including Germany, Italy, and Japan). The war concluded with the unconditional surrender of the Axis Powers in 1945.
These two wars had a profound impact on the world, leading to significant political, social, and economic changes.