Diode is a two electrode device only, which is essentially a PN junction and the P-type semiconductor N-type semiconductor. With the "forward pass, reverse cut-off" feature, allowing only one direction the current flows in the circuit can be completed rectification, detection, regulation and other features. Depending on its use, but also can be divided into rectifier diode, detector diodes, zener diodes, light emitting diodes, switching diodes and other.
