I posted this answer:
Fascism and Communism are not philosophically polar opposites. Philosophically, these two ideologies are “cut from the same cloth”. Both are collectivist. Both are statist. Both are uncompromisingly anti-individualist and anti-Capitalist. Both reject private property rights, free trade, and freedom of speech.
Where they differ is in practical implementation, but only superficially. For example, economically, Communism features state ownership of “the means of production”—meaning, no private ownership of property and business. Fascism features state control of the “means of production”—meaning, state permission of superficially private ownership of property and business, but without private rights to use and control. In this economic regard, a Fascist can be summed up as a practical Communist.
Fascism and communism go hand in hand—that is, both Fascism and Communism feature totalitarian control over all aspects of society, including education, religion, and information—because they are not philosophically polar opposites. The implementation of that control varies, and it makes no difference whether they are democratic or not. Both always involve the subordination of individuals to the collective, via state power. Politically, they are deadly enemies. But their conflict is not fundamentally philosophical. Their conflict is akin to rival underworld Mafia mobs fighting a turf battle—e.g., Nazi Germany vs. Soviet Russia. Philosophically, Fascism and Communism are fraternal twins, not polar opposites. The only polar opposite of both is Capitalism.
I have dealt with these issues extensively. Here are two answers that should be particularly helpful:
QUORA: Why do people find communism so terrifying as an idea?