What is the function of switching diodes?

What is the function of switching diodes?
There is a PN junction in the switching diode. When there is a forward current, the current flows and leads to the positive current. When the negative charge comes, the diode does not turn on. It can switch and isolate in the circuit.
The switching diode makes use of the unidirectional conductivity of the diode. After adding the forward bias voltage to the semiconductor PN junction, the resistance in the on state is very small (tens to hundreds of ohms); coupled with the reverse bias voltage, the resistance is very high (the silicon diodee is more than 100m ohms). Making use of this characteristic of the switching diode, it plays the role of controlling the current passing through or turning off in the circuit and becomes an ideal electronic switch. The forward resistance of the switching diode is very small, the reverse resistance is very large, and the switching speed is very fast.