The theory of communism examines the structure and evolution of human civilizations. According to the theory, society is edging closer to the ideal where everyone self-organizes to complete necessary tasks and everyone makes thoughtful consumption decisions that strike a balance between personal wants and the demands of the community.
The phrase "from each according to their capacity, to each according to their need" can be used to describe this concept.
According to the notion, capitalism opposes communism. According to the argument, capitalism is undesirable because it unfairly distributes commodities and services, resulting in some people receiving more than they require and others being forced to contribute more than they can manage. But because of its intrinsic strength, capitalism will strive to protect itself. Overcoming capitalism is necessary to reach communism.
A middle path between capitalism and communism is socialism. Socialism is an economic system where who makes what, for whom, and who gets what is decided by a central technocratic bureaucracy. According to communist doctrine, socialism must be introduced as a replacement for capitalism before communism can be achieved. Since socialism is naturally democratic and the majority of workers outweigh the smaller group of individuals who control the capital, if you can convince the workers to act in unison you can break the capitalist hold on society. This is why socialism can defeat capitalism. According to communist philosophy, after achieving socialism, people would naturally move toward communism and no longer require centralized bureaucratic planning.
Consequently, the forces of revolution are represented by communists and socialists. They contend that resistance to capitalism requires a war. People who support communism and are prepared to take direct action are harmful to a capitalist society because they are engaged in a civil war and may be prepared to utilize unconventional measures to further their goals. Since we tend to promote the idea that it's a good thing when slaves are freed and that fighting to free slaves is one of the times when physical violence may be justified, they are seen as particularly dangerous in this regard because communist philosophy sees the workers as slaves to the capitalist system.
That's the theoretical problem.
The issue in the actual world is that when a country adopted communism, it tended to take part in activities intended to further communism. It provided funding for agents who would incite violence and strive to weaken non-communist civilizations. The first big communist nation was Russia, and Russian communists were active across Europe in an effort to spark communist revolutions. The second major communist nation was China, which actively promoted communist revolutions throughout Asia. The third major communist revolution took place in Cuba, and the country's citizens made a great effort to spread communism throughout South and Central America. Many people today dread communism because of this clear connection between it and revolution.