USB 3.0 is much faster than USB 2.0. USB 2.0 offers a top speed of 480 Mbps, while USB 3.0 offers transfer rates of 4.8 Gbps. Also, USB 2.0 is usually grey or black, while USB 3.0 is usually blue to differentiate it from 2.0. ... The primary purpose of USB, which stands for Universal Serial Bus (USB), is communication.Nov 28, 2016