Law is intended to, at a fundamental level, reflect and enforce the moral and ethical standards of a civilised society. The first thing that should be understood is the slight difference between morals and ethics.
Morality deals with that which is regarded as right or wrong. Morality stems from an individual's conscience and from the values of a given society, which might be based on religious tradition or on political principles such as democracy or socialism. Moral conduct would be that which is considered 'right' based on people's consciences and society's shared values. Morality is one way for a community to define appropriate activity.
Ethics (from the Ancient Greek word ethikos meaning 'theory of living'), is a type of philosophy which attempts to figure out that right versus wrong in any given situation or scenario. In general terms, ethics are practical moral standards that distinguish right from wrong, and give us a guide to living 'moral' lives. These standards might include duties that we should follow, such as fidelity in marriage, or the consequences of our behaviour on others. The act of embezzling money from a company, for example, is not only a legal wrongdoing against the company but also an action that could result in people losing their jobs. In more specific terms, some of the more difficult ethical questions on which a government might legislate could include issues relating to abortion, euthanasia and animal rights.