MTU: Maximum Transmission Unit, the Ethernet MTU is 1500 bytes
the MSS: maximum resolution size, the segment size of each TCP packet of the maximum data for each transmission, the receiving end notifies the transmitting end, the transmission will be larger than the MTU fragmentation
The minimum length of TCP data 1460Bytes
this to do with specific transport network, Ethernet MTU is 1500 bytes, Internet MTU of 576 bytes.
MTU is a transmission unit of the network layer, the MSS = MTU - 20 bytes (IP header) --20 bytes (TCP header). So Ethernet MSS is 1460 bytes, the Internet MSS is 536 bytes.
Maximum load 65535-40Bbytes TCP
maximum segment payload of the TCP packet is 65495 bytes, because each segment must fit into the IP payload capacity, no more than 65535 bytes, 20B IP header, TCP header 20B, so that a maximum load of 65535 20-20 = 65495B