At my mom’s funeral we had no body or casket or urn of ashes (she was cremated). It actually seemed a little odd to me, to have nothing of her there, but as someone else said it was really for all of us, and it was immaterial if any of her corporeal remains were there–actually or symbolically. We may have called it a “memorial” service but I don’t recall.
I forgot about that variation in theology and its consequences for the deceased. I hope I have your indulgence for my omission! 
When your body is willed to science ,this is also the case. I was at a church ceremony held in such a case. It seemed to me very clean and simple. I think they had what appeared to be an empty casket. Lots of pictures were around.
Many opt for a memorial service in lieu of a funeral.
Of course there is little if any difference but the name.