Communism
The word "communism" is not a very specific description of left-wing political organizations. Many political parties calling themselves "communist" may actually be more reformist (supportive of reforms and slow change instead of revolution) than some parties calling themselves "socialists". Many communist parties in Latin America have lost many members because these parties do different things than what they promised once they get into power. In Chile, between 1970 and 1973, under the left-wing Coalition (groups of parties) of Popular Unity, led by Salvador Allende, the Communist Party of Chile was to the right of the Socialist Party of Chile.  This means it was more reformist than the socialist party.