Are Luna and Lunc the same?

Could you possibly clarify for me if Luna and Lunc are indeed interchangeable terms, or are they distinct entities with unique characteristics? I've been hearing these two names used interchangeably in some crypto discussions, but I'm not entirely sure if they refer to the same thing. If they are different, what are the key differences between them? And if they are the same, what's the reason for the two different names being used? I'm trying to get a better understanding of the cryptocurrency landscape, and this seems to be a point of confusion for me. Could you help me sort this out?