Something that makes a real contribution to society. Like a fireman, ambulance officer, carpenter or builder.
I would say a fireman, EMT, doctors, they are saving lives, a massive life and death contribution to society.
A carpenter or builder is not.
Nothing against carpenters and builders, I actually was one once. Just that comparing the levels of contribution to society, if that's the definition, with that of the former, is incomparable.
Apples and oranges