USB version numbers:
There are different version numbers (1.0, 1.1, 2.0, and 3.0). These numbers refer to the transmission speed. The higher the version number, the higher the speed. To achieve this speed, however, host device, cable and terminal device must have all this version number. If this is not the case, the element with the weakest USB version determines the speed.
Example: If your computer has a USB 2.0 port, your USB 3.0 cable and your smartphone also USB 3.0, then you will reach the speed of USB 2.0. Only if all three elements (computer, cable and smartphone) have USB 3.0, you will reach the speed of USB 3.0.