Bolshevism

Bolshevism refers to the ideology of the Bolsheviks and the Communist Party of the Soviet Union (Bolsheviks). It is not to be confused with Marxism–Leninism, which was developed from Bolshevism by Joseph Stalin in the 1920s. Bolshevism entails a vanguard party operating with almost military discipline under the principle of democratic centralism. The vanguard party will mobilize the proletariat (in alliance with the peasantry) for social revolution and the construction of a dictatorship of the proletariat. While doing this, the party will be constantly criticizing and self-criticizing along with purging opportunists and factionalists from the party.^[1]

References

↑ Joseph Stalin (1924). Foundations of Leninism, "The Party". Available on the Marxists Internet Archive.
"The Party becomes strong by purging itself of opportunist elements."

v t e Leftist tendencies
All of these ideologies claim to be forms of socialism or communism.
Anarchist	Mutualism, Anarcho-communism, Anarcho-collectivism, Anarcho-syndicalism, Without adjectives
State	Bolshevism (Marxism–Leninism, Maoism, Trotskyism, Titoism, Hoxhaism), Left communism (Council communism, Bordigism), Impossibilism, Libertarian Marxism
Reformist	Democratic socialism, Eurocommunism, Social democracy (Orthodox Marxism)