What's a funeral and why is it weird?

My mom insisted that I go to our grandfather's "funeral" and so we went there. I saw my grandfather sleeping in a sort of special bed or something. They called it a coffin (Isn't that where vampire's sleep?). A lot of people are watching him (Which is sort of weird). We've been in this "funeral" for about 6 hours now and he still hasn't waken up. And why are people crying?