The switch can transfer data between multiple port pairs at the same time. Each port can be considered as a separate physical network segment (note: Non-IP network segment), the network device connected to it enjoy all the bandwidth alone, without competing with other devices. When node A sends data to node D, node B can send data to node C at the same time, and the two transmissions all have the full bandwidth of the network and have their own virtual connections. If a 10Mbps Ethernet switch is used here, then the total amount of the switch is equal to 2x10mbps=20mbps, and the total flow of a hub will not exceed 10Mbps when using the 10Mbps shared hub. In short, the switch is based on MAC address recognition, can complete the encapsulation and forwarding of data frame function network equipment. The switch can "learn" the MAC address and store it in an internal address table, by establishing a temporary exchange path between the originator of the data frame and the target receiver, so that the data frame is reached at the destination directly from the source address.