Capitalism is an economic system characterized by private ownership and control over the means of production. The distribution of goods and services and their prices are mainly determined by competition in a free market. Under such a system the primary job of government is to protect private property, enforce contracts and ensure rule of law.
There has never been a pure free market capitalistic system just as there has never been a pure communist or socialist system, where there is government ownership of the means of production and each individual has equal access to society's resources. However, we can rank economies as to whether they are closer to capitalism or closer to communism or socialism. If one ranked countries according to whether they were closer to the capitalistic end of the spectrum or the socialistic or communistic end, then ranked countries according to per capita GDP and finally rank countries according to Freedom House's "Map of Freedom in the World," he would find a pattern that is by no means a coincidence. The people in those countries closer to the capitalist end of the economic spectrum have far greater income and enjoy greater human rights protections than those toward the socialist and communist end.