What is utilitarianism?

Utilitarianism is a consequentialist normative ethical theory. Consequentialist theories hold that an action is right insofar as it creates the best possible consequences. For utilitarians, the best possible consequence is the creation of the most utility. Utility is often referred to as happiness. Utilitarianism therefore, is the idea that morally right actions are those which create the greatest amount of happiness overall, commonly phrased as "the most happiness for the greatest number of people". Famous utilitarian philosophers include Jeremy Bentham and John Stuart Mill.