They are a set of principles and rules concerning the conduct of man, not only with himself, but in his relations with God and with his fellow men, refers to the notion of good and evil.
They are part of God's natural law, which is written in our conscience, and as we sometimes forget them, we must constantly be reminded.
They have been around forever. Socrates and Plato already said that man should act according to his conscience, practicing the virtues, choosing good and moving away from evil.
God's law was docilely divided into 10 moral laws:
10. Justice, Love and Charity.