Social inequality is the existence of unequal opportunities and rewards for different social positions or statuses within a group or society. Although the United States differs from most European nations that have a titled nobility, the U.S. is still highly stratified. Social inequality has several important dimensions. Income is the earnings from work or investments, while wealth is the total value of money and other assets minus debts. Other important dimensions include power, occupational prestige, schooling, ancestry, and race and ethnicity.