Ethics is the foundation of knowledge that describes right/wrong or better/worse. It applies to issues of harm/care and fairness/reciprocity. It is universal. It transcends culture, religion, and time. It is conditional; not to be confused with relative.
Ethics is absolutely knowable but given ethical circumstances occur between two entities in time, many factors are involved in judging ethical acts. Absolute right or wrong conditions are rare. Typically, ethical acts fall somewhere along a grey scale – the space between black & white. Right and wrong seem like relative terms when incorrectly applied to a grey world. Better or worse is sometime the best approximation to truth we can obtain.