The main difference between the USB interface and the socket is the difference in the use function and the function mode. The USB interface is mainly connected to other USB devices for data transmission. The USB socket its main use is to use the USB jack on the socket for power supply and other ways, can not transmit data. It's their nature. That's the main difference.
The socket generally refers to the 220 volt socket in the family, in the factory is 380 volts he is used for some household appliances lighting, and the processing equipment used in the factory, the USB interface is a low-voltage output only 5V is used to charge some small household appliances.
USB is a DC voltage output through 220 volts after rectification, charging DC electrical equipment