Nazism was the ideology behind the National Socialist Party (Nationalsozialismus) which ruled Germany from 1933 to 1945.
Led by Adolf Hitler (1889-1945) the party rose to prominence in a heavily demoralised Germany left reeling from defeat in World War I, shamed and angry over the 1919 Versailles Treaty (which insisted that Germany assume sole responsibility for the war) and the blights of the worldwide Great Depression. The party was elected in 1933.
The Nazis claimed to offer a “third way” to the people of Germany – neither capitalism nor communism, the dominant ideological poles of the time. They promised a nationalist form of socialism that would provide for their people, who they believed were the summit of the Aryan race (to them, the Master Race). This particular strand of fascism held that the biggest threat to said race and Germany’s future was the Jews, who they considered to be a parasites bent on self preservation through alignment with Enlightenment values like liberalism, democracy, parliamentary politics, capitalism, industrialisation, Marxism and trade unionism. Unsurprisingly, all such things were anathema to the Nazi party.
It is one of humanity’s greatest failures.