multicast packet deals with and routers

suppose a group of machines have the same ip address like 60.4.4.4 so router can send the packet to that network but here the every node will take care to deliver the packets to target (multiple routers) there is no need that grand parent(main sender) will take care of all family members wether they got the food(data packets) here the grand children (which is not directly with sender ) food(data packets) send by his children of grand parent(which is directly connected with the sender) so here router send the data to packets and all the nodes send the packets to the a physical address link up with that ip

unicast also deals with routers it will deals with one-to-one connection every parent have the direct relation with child