Capital, crucial to capitalism, signifies financial wealth used for business investment, distinct from personal savings or housing.  Capitalism empowers private individuals with capital to invest, profit, and retain earnings, contrasting sharply with communism's state-owned property and centralized production.  Marxist theory highlights the class struggle between the bourgeoisie (capitalist minority owning capital and profiting from investments) and the proletariat (working-class majority lacking capital, reliant on wages).  Private property is fundamental to capitalism; its protection ensures capitalists retain investment returns, unlike under communism's state redistribution.