viewport size

Hello,
i was reviewing unrealMatch3 and tappyChicken examples because of i want to learn how to adjust the camera. Tappychichen uses “get viewport size” node from “get player Controller” and UnrealMatch3 uses “get viewport size” node from HUD.
I have tested these nodes and they have the same values, then:
Is there some difference between these nodes? if not, Can i say that the size of the HUD canvas is equals to size of game viewport?

regards!