Usb Data Transfer Rate. Usb 30 renamed usb 31usb 32 gen1 superspeed. As the name usb 30 indicates it is the third version of usb.
Usb 32 renamed usb 32 gen2x2. Usb 20 renamed usb 20 hi speed. They can optionally support 40 gbps 48 gbsec if they use the shorter 08 meter gen 3 cable.
You should note however that it does not always live up to its potential.
Usb 31 renamed usb 31usb 32 gen2x1 superspeed. Usb4 devices are required to support 20 gbps 24 gbsec. Usb 30 is capable of 48 gbps of data transfer rate which is more than usb 20s 480 mbps. 15 megabits per second mbps usb 11full speed.