Diode is one of the building blocks of electronic circuits. There are different types of diodes, each with it is own operating characteristics and applications. The various diode types are easily identified by name, circuit applications and schematic symbol. It should be noted that the term diode, used by itself, refers to the basic pn-junction diode. Different diodes has different names, such as zener diode, light emitting diode and therefore on. In this section we’ll learn more about diodes.