Ethics is a branch of philosophy which called another name moral philosophy. It determines the standard of human behavior, what is right or wrong behavior. These fields consist of the branch of philosophy called axiology. Ethics want to solve human morality such as right or wrong, justice and crime, good and devil. Philosophers classified ethical theories into three areas: metaethics, normative ethics, and applied ethics. Metaethics describes the origin of ethical principles and their significance and tries to find the answer. Metaethics focus on universal truths. Normative ethics is comparatively more practical. They measure our good and bad behavior and our attitude to others. Applied ethics involves specific controversial issues, such as infanticide, abortion, homosexuality, environmental concerns, animal rights, nuclear war, capital punishment. Through these three major ethical studies, our society tries to resolve controversial issues.