Altruism may be defined as unselfish regard for or devotion to the welfare of others. The term derives from the Latin alter, “other”, and was coined and adopted generally as the opposite to egoism
Altruism is in ethics a theory of conduct that regards the good of others as the end of moral action.
Altruism, in biology, is an action that benefits the receiver but comes at some cost to the performer. There are various evolutionary explanations for why this may occur.