Happiness is a state of mind or feeling characterized by contentment, love, satisfaction, pleasure, or joy. A variety of philosophical, religious, psychological and biological approaches have striven to define happiness and identify its sources.

Philosophers and religious thinkers often define happiness in terms of living a good life, or flourishing, rather than simply as an emotion. Happiness in this older sense was used to translate the Greek Eudaimonia, and is still used in virtue ethics.

While direct measurement of happiness presents challenges, tools such as The Oxford Happiness Questionnaire have been developed by researchers. Positive psychology researchers use theoretical models that include describing happiness as consisting of positive emotions and positive activities, or that describe three kinds of happiness: pleasure, engagement, and meaning.

Research has identified a number of attributes that correlate with happiness: relationships and social interaction, extraversion, marital status, employment, health, democratic freedom, optimism, religious involvement, income and proximity to other happy people.

Happiness economics suggests that measures of public happiness should be used to supplement more traditional economic measures when evaluating the success of public policy.

Source: Wikipedia