How to make Difference between USB 1.0, 2.0 and 3.0 ?

USB, short for Universal Serial Bus, is an industry standard developed in the mid-1990 that defines the cables, connectors and communications protocols used in a bus for connection, communication, and power supply between computers and electronic devices.

USB 1.0  -> Its transfer speed is 12 Mbps

USB 2.0  -> Its transfer speed is 480 Mbps

USB 3.0  -> Its transfer speed is 4.80 Gbps