Diodes are semiconductor devices that allow current to flow in one direction while blocking it in the opposite direction. They are essential components in various electronic circuits, serving functions such as rectification, voltage regulation, and signal modulation. Common types of diodes include Zener Diodes, Schottky Diodes, and Light Emitting Diodes (LEDs). The operation of a diode is based on the properties of semiconductor materials, typically silicon or germanium. When a diode is forward-biased, it conducts electricity, while in reverse bias, it prevents current flow. This unique behavior makes diodes crucial for protecting circuits and ensuring proper functionality in devices like power supplies and radio transmitters.