What are the differences between all the different forms of government historically referred to as Communism?

Hi! You may be interested in these previous answers, which I think cover your question fully:

What is the difference between: Maoism, Leninism, Stalinism, Trotskyism and Marxism? Answer from /u/khinzeer
How different was Mao's communism from Marx's commuism? What about the Russian figureheads like Stalin, Trotsky, or Lenin? Answer from /u/jrhistorian
What are the discernible differences between the various Communist systems? What separates Mao from Pol Pot from Tito from Stalin, etc? Answer from /u/yodatsracist

And finally, there is this writeup in /r/socialism, by /u/ainrialai. Mods, please let me know if linking to other subreddits is not allowed, and I'll remove this portion of the post.