Social class is defined in different ways by Marx and Weber. Marx saw social class as defined by access to resources and means of production, dividing society into owners and workers. Weber defined social class based on wealth, power, and prestige, seeing a hierarchy with different levels. In the U.S., income and wealth are highly concentrated among the top 20% of the population, while the bottom 20% receive a very small share, a distribution that has changed little over time. Social class has consequences for factors like health, education, politics, and crime, and mobility between classes is limited. Poverty disproportionately impacts certain groups and persisting poverty can span generations.