Meta ethics focuses on the underlying framework behind morality. Whenever you’re asking, “But why is it moral?” That’s meta ethics.

Meta ethics splits between cognitivism (moral statements can be true or false) and non-cognitivism (moral statements are not true or false). One popular cognitive branch is natural moral realism, the idea there are objective moral facts. One popular non-cognitivism branch is emotivism, the idea that moral statements all all complicated “yays” or “yucks” and express emotions rather than true/false statements.

Cognitivism also has anti-realism, which is there are moral facts, but they are truth/false conditional based on each person or group. My issue is you lose the ability to call out certain behavior as wrong; slavery is wrong; not respecting others is wrong. If you want to believe all morality systems are valid, meaning your morality is no better than some radical thought group’s, then go ahead. On an emotional level, speciesism level, rights level, deontological level, utilitarian level, and many more slavery is wrong. Again, some nut job doesn’t invalidate all other thoughts. That’s my take.