I already defined the first one.
A refugee is someone who is fleeing tyranny such as a Christian fleeing Muslim genocide. Many claim to be refugees who are not. But they understand, this is their quickest path to legalization.
I don’t use the term illegal immigrant. An immigrant obeys our immigration laws. I used the term illegal invader. They do not obey our immigration laws.
I have a sister in law and brother in law who are legal immigrants. They both respected our laws and came here legally. I simply refer to them as Americans.
I hope this helps.