"Normative ethics concerns questions about right and wrong and the criteria to distinguish them. It is not about how the world is, but about how it should be. More accurately, normative theories attempt to delineate what is correct use of action-guiding or prescriptive terms as ought, value, good, should, duty, obligation, right, wrong, permissible or forbidden. This makes normative inquiry different from scientific inquiry. Regarding the latter, what scientists find out about the world is not qualified in terms of ‘right’ or ‘wrong’. Science is deemed devoid of normativity; instead, it is a purely descriptive and explanatory endeavor. As such descriptive ethics is a part of science and does not in itself prescribe: it merely describes how people use normative ethical terms."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3068523/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3068523/