Question: what is usb 3 and 2?
Answer: USB 2.0 offers transfer rates of 480 Mbps, and USB 3.0 offers transfer rates of 4.8 Gbps — 10 times faster. ... USB 2.0 provides up to 500 mA whereas USB 3.0 provides up to 900 mA. The USB 3 devices provide more power when needed and conserve power when the device is connected but idling.