There is no single, absolute definition of ethics as a discipline because it is constantly evolving as a result of a change in socio-cultural and political context.
In the Judeo-Christian tradition, the ideals of righteousness before God and the love of God and neighbor, not the happy or pleasant life, constitute the substance of ethics.
According to Terrance McConnell, morality is characterized as an 'end-governed rational enterprise' whose object is to equip people with a body of norms (rules and values) that make for peaceful and collectively satisfying coexistence by facilitating their living together and interacting in a way that is productive for the realization of the general benefit.
In the first sense, morality refers to "code[s] of conduct put forward by a society or a group (such as religion), or accepted by an individual for her own behavior".
Applied ethics is the actual application of ethical or moral theories for the purpose of deciding which ethical or moral actions are appropriate in a given situation.
Casuists, the adherents of applied ethics, are concerned with individual moral problems, such as abortion or euthanasia, and attempt to resolve the conflicting issues that surround these particular moral problems.
The difference between the three major types of ethics can be illustrated in the following situation: A police officer shoots a terrorist who is about to blow up a crowded shopping mall.
If a moral philosopher attempts to address the questions "What is good?", "What is justice?", "Why should I be moral?", then that moral philosopher is doing metaethics.
From teleological, to deontological and consequentialist ethics, and to their recent variations, one is offered different moral principles which overlap, conflict, and diverge in many ways.