Moral Theology is the subdiscipline of Theology that works with matters of moral judgment. Outside of Catholicism but within Christianity, this is often called Christian ethics. Moral Theology is a broad subject that addresses sin and grace, conscience, and development of virtue in a wide variety of contexts, and uses scripture and tradition as its prime resources.
Although there is overlap, most contemporary social concerns are addressed more directly in a branch of Moral Theology called Catholic Social Teaching.

Wikipedia Image
Depicted is the famous Sermon on the Mount of Jesus. Painting by Carl Heinrich Bloch, Danish painter, d. 1890.