USB debugging enables Android developers to remotely control devices.
USB debugging (also called remote debugging) is an Android developer option. It facilitates operating mobile devices using a desktop computer.
It usually suffices to have an USB driver installed suitable for the device being debugged. Google Chrome is then used to inspect connected devices. Naturally, the “USB debugging” setting needs to be activated on the respective device. Another common means of accessing USB debugging options is ADB.
For further reading, see Remote Debugging Android Devices at Google Developers.