Relativism is a form of non-cognitivism, which is the view that there is no objective moral truth, and that moral statements do not express beliefs.
Descriptive relativism claims that moral codes differ from one society to the next. For example, according to one society, slavery might be permissible; to another, it might never be permissible.
From this claim, some people infer normative relativism. This is the view that because cultures make different moral judgements, and there is no 'neutral' standpoint we can judge them from, we should tolerate them and consider them valid.
As a result, to talk of what is morally right makes sense only in relation to a specific, culturally relative morality. So, right in a culture = right according to that…