Huh. I'm surprised how many people
didn't know they were the same thing. But then again, maybe that's because around here cilantro is common as dirt and nobody carries exotic Indian things like "coriander." If you want coriander at all, you have to know it's really cilantro.
What's the other big thing that goes by two names...? Oh yeah, scallions and green onions. Those are the same too.