Who are "conservatives"? Who are "liberals"?

Many people in the US think that the antonym of "conservative" is "liberal". I think that this dichotomy is strange.

I think that if "conservative" means trying to preserve or protect something, its antonym should mean "changing" something. On the other hand, what is the antonym of "liberal"? If it means freedom of something, its antonym should mean "restriction" or "ban" of something.

Conservative are liberals, and liberals are conservatives.

Environmental protection, gun control, ...
I think that people who call themselves "conservative" in the US tend to want more climate "change" and looser "restrictions" on selling guns. I don't think they are entitled to be called "conservatives".