Many of the methods and forms used by Stalin and Hitler were quite similar. Both men employed propaganda and terror to gain and maintain power, though Hitler tended to utilize speeches, both public, and on the radio, than Stalin did. Both engineered bloody purges of party members, including many that had been instrumental in their rise to power. Both employed secret police to tamp down dissent, which was punished harshly, often with incarceration in forced labor camps. Both, additionally, maintained a single-party state.
Many of the differences between the two were ideological, though ideology frequently bled into policy. Hitler nationalized some industries, but the sort of collectivization project embarked upon by Stalin was not part of his program. Additionally, the ideological foundations of Hitler's regime were based upon ultranationalism and a racist vision of the German state; Stalin's on the overthrow of capitalism.