Moral absolutism
: there are facts about which actions are right
and wrong, and these facts do not depend on the perspective,
opinion, or anything about the person who happens to be
describing those facts.
Moral nihilism
: there are no facts about which
actions are right and wrong.
Moral relativism
: actions are not right or wrong “in
themselves”, but only relative to a person or group. An action
is right relative to a person or group if and only if the action is
right according to the standards adopted by that person or
group.
Meta-ethical moral relativists believe not only that people disagree about moral issues, but that terms such as "good", "bad", "right" and "wrong" do not stand subject to universal truth conditions at all; rather, they are relative to the traditions, convictions, or practices of an individual or a group of people.
So meta-ethicists are just as morally relativistic as the post-modernists they condemn.