This animation shows several computers connected to a switch.  Host 1 wants to send a packet to a server (a unicast).  The diagram shows the MAC address and IP address of both host 1 and the server.  The graphic also shows the frame with source and destination MAC address and the encapsulated packet with source and destination IP address.  When the animation plays, the frame travels from host 1 to the server since the switch forwards the frame based on MAC address and knows where the server is located.