Objective morality is the idea that a certain system of ethics or set of moral judgments is not just true according to a person's subjective opinion, but factually true. Proponents of this theory would argue that a statement like "Murder is wrong" can be as objectively true as "1 + 1 = 2." Most of the time, the alleged source is God, or the Kantian Categorical Imperative; arguably, no objective source of morality has ever been confirmed, nor have any a priori proofs been offered to the effect that morality is anything other than subjective.
The moral principles that people claim to be "objective" usually coincide very well with what they feel subjectively to be true. When pressed to provide justification, the person in question will usually just fail to understand that morality might not be objective, and might consequently grow increasingly doubtful or hysterical as the subjective bases of their arguments are progressively revealed, as has been observed in recent times.
Most of the objective morals promoted today in the West are grounded in Christianity. Among Christians, it follows from the ideas of inherent human sinfulness and original sin that one's subjective moral instincts must be categorically classed as evil. Thus, say the Christians, one needs an external, objective source for morality. And — speak of the devil — there is such an external, objective source to be found at a nonspecific location in the sky, sitting on a throne.
The Catholic Church originally admitted several sources for such morality, including human reason; but at the Protestant Reformation, when the principle of "total depravity" was promulgated to an unprecedented degree, human reason became very dodgy and the Bible became the only source that was not suspect. Hence, we see creationists arguing that there are no meaningful morals if Genesis 1 is not true to the letter.
Morality has no edges, because there are no actions you can say are definitely evil. Almost any action can be justified if you try hard enough. If there was a definitely evil action, it would be completely unjustifiable in any way, but since there can be a reason for anything, there are therefore no edges to morality.
There are certain things that most people in society who would consider "bad" or "evil" but a lot of these stances cannot be explained with objective reasoning. Unless you are religious, morality is totally subjective, even if most will agree on basics like murder and theft being wrong. I consider something to be wrong if it ends in anyone being hurt or negatively affected in any way although even this relies on the assumption that everyone being happy is a good thing. Someone else may think that anything is fine as long as they are happy and I'd strongly disagree, I'd argue, and both of us would walk away with our own, separate, subjective moral values
There is no definite definition of right and wrong; the moral of a given action is not determined by the intention or consequence, context and perception play roles. Most of society defines and perceives right and wrong in an unambiguous manner, but defining right and wrong is more complex than people think.
Some things are wrong: Raping babies will always be wrong no matter where on earth you go. There is no reason this could be good. If you had the choice between raping a baby or killing a baby you would probably kill it. This is an extreme example but you get the point.
Morality is the study of what is good and bad for us. That's relative rather than absolute, because by definition we have good and better; bad and worse.
Morality is also contingent on context because while it's good to give a starving man a sweet drink, it's not good if that man is diabetic.
Morality is also informed by subjective experience because while the sight of blood isn't traumatic to (say) a doctor, it might be to someone suffering PTSD.
However morality isn't arbitrary. We know that compassion is good because our individual and collective welfare depend on it; we know that abuse of power is bad because it corrupts and destroys not only our lives, but the societies we depend on.
If we are willing to abandon traditions and laws, we are free to examine harm and weal from a humanistic perspective: one where we explore empirically and compassionately our impacts on others. That can give us more than one defensible answer, but doesn't exclude common ground, or make every answer equally legitimate.
Morality is morality. Morality without edges simply isn't morality anymore. It's just loose guidelines that no one listens to. Maybe it's a lot looser for some people or religions than others. Some things in the world (( like the example above: raping babies )) will probably never be viewed as an OK thing to do. I believe and hope it should NEVER be OK.
It is just not right to swear, insult people or countries or race, kill people, try to make fun of people, countries, races, make people slaves, servants or do things against their will. Those things will always be wrong wherever you go in the world, or even the universe. Maybe even a multiverse.