What is the actual basis on which ethics, as well as morality, should be based, determining what a person considers right or wrong?

Worldviews

What is a worldview?

What is the actual basis on which ethics, as well as morality, should be based, determining what a person considers right or wrong? Regarding the things that people know to be true,

What is the basis of their beliefs and how can people justify their knowledge and the process of understanding what they think they know?