Please read the whole thing or don't bother commenting as the bottom part is important.
I don't think most people understand what communism is, it's a theory or system of social organization in which all property is owned by the community and each person contributes and receives according to their ability and needs.
There are two classes in society, the working class, who make up the majority of the population within society and must work to survive, and the capitalist class, a small minority who derives profit from employing the working class through private ownership of the means of production. The theory is that communism would put the working class in power and in turn establish social ownership of the means of production.
Along with social democracy communism became the dominant political tendency within the international community by the 1930s with generally one side (the west) advocating for social democracy and the other side advocating for communism.
Most people base their opinion on communism on propaganda from the cold war mainly based around the failed soviet model of communism although most academics and economists, among other scholars, posit that the soviet model under which these nominally Communist states in practice operated was not an actual communist economic model in accordance with most accepted definitions of communism as an economic theory but was in fact a form of state capitalism, basically true communism has never been in existence.
Basically the theory is that communism would hand back the power to the people rather than the top 1% who maintain control and thrive under social democracies and have most of the wealth and influence over the population.
It's said that social democracy is a sort of slavery designed to keep the majority of wealth and power in the hands of the few, The wealthiest 1% of Americans controlled about $41.52 trillion in the first quarter, according to Federal Reserve data. Yet the bottom 50% of Americans only controlled about $2.62 trillion collectively, which is roughly 16 times less than those in the top 1%.
In theory if communism could actually work the way it is said could possibly work, the top 1% would never allow it to happen as it would strip them of most of their power and influence.