The wire that can come up is alternating current, which can be pulled off the building and plugged into a socket to recharge. When an electric current passes through a wire, it creates a magnetic field that can pass through air and some objects, transmitting electricity directly. This is the basic principle of wireless charging. Now there are many wireless charging technologies are widely used, including electromagnetic induction charging, magnetic resonance charging, laser charging and so on. These wireless charging technologies can bring more convenient and efficient charging methods, gradually changing people's lives.