A memorial service is usually held some time after the death. It might be an additional service held some time after the funeral. There are many reasons you might want to have a memorial. One of the most common is when a person was living interstate or overseas, but you want to hold another service for friends and family who couldn’t be there. But there are many other reasons too: often, people will have a smaller ceremony for the interment of ashes; if it was a sudden or unexpected death you might need time to think about what you want to do, so decide to have the burial or cremation then hold the ceremony at a later time; perhaps an important person was travelling overseas or couldn’t be there for some reason. For all these reasons and many more, you might want a memorial service.