What are forward bias, reverse bias and unidirectional conduction of diodes?

Forward bias means that the positive terminal of diode is connected with high potential and the negative terminal is connected with low potential.

Reverse bias means that the positive electrode of the diode is at a low potential and the negative electrode is at a high potential.

Unidirectional conduction refers to the unidirectional conduction of diodes. When the diode is forward biased, the on-resistance is very small, and the on-voltage drop is about 0.7V (silicon tube). Equivalent to access. When the diode is turned off by reverse bias, the resistance tends to infinity, which is equivalent to an open circuit state.