Is the difference between free-range-eggs and normal eggs just lies on its virtue?

Question

or is it has anything to do with the quality of eggs, the vitamin or whatever inside the eggs? Can you also give me the reference? Thanks!

Answer 1

anything free range means that the animal walks freely as opposed to for example a chicken that stays in a coop  

Answer 2

"Normal eggs" come from the chickens who more than likely were caged with just enough room to stand up or sit down, sometimes not even being able to turn around. Others come from chickens who are only allowed inside in coops.

Free-range eggs come from chickens who are allowed to run free in an enclosed area and lay eggs as they wish. It's known as the more humane way for chickens to lay eggs.