It's a proof of an address, akin to soviet-style "propiska", which was very important and hard to get without (it also affected ownership/inheritance).
What's more fun is that even though they accept different types of residence, they mostly trust utility bills -- but to set up utilities on your name even for your personal home utility company will ask a lot of documents, including credit score checks.
I personally felt that it's utility companies who do the heavy proof checking, not DMVs.
RealID is unrelated to citizenship.
It's a proof of an address, akin to soviet-style "propiska", which was very important and hard to get without (it also affected ownership/inheritance).
What's more fun is that even though they accept different types of residence, they mostly trust utility bills -- but to set up utilities on your name even for your personal home utility company will ask a lot of documents, including credit score checks.
I personally felt that it's utility companies who do the heavy proof checking, not DMVs.