As you already know the current that flows through a diode cannot flow in more than one direction. Now this condition is a forward bias condition. For making it more simpler, you can consider diodes as some kind of electronic valves which regulate the current flow so that the device can keep working normally. In case a diode is experiencing a negative voltage, there will be no current flowing which will make your diode an open circuit. Besides a forward bias condition, there is also a reverse bias diode condition. Basically, biasing means that the diode is determining different amounts of voltage and current at different spots in a circuit. The diodes include semiconductors as fundamental units in their structure. The semiconductor diode has two sides called P-type and N-type. In the center, there is a P-N junction. There are also some leads connected to these diodes which make the assembling of these diodes in consumer electronics much easier.
