LED, English name Light Emitting Diode, LED, is a solid-state semiconductor device that can directly convert electrical energy into light energy.
The core of the LED is a semiconductor wafer. The wafer consists of two parts, a part of which is a P-type semiconductor. Inside it, holes are dominant, and at the other end, it is an N-type semiconductor. Here, it is mainly electrons.
When these two types of semiconductors are connected, a "P-N junction" is formed between them. When current flows through the wire to the wafer, the electrons are pushed to the P area. In the P area, the electrons recombine with the holes, and then they emit energy in the form of photons. This is the principle of the LED light.