Why Trust Techopedia

What Does Diode Mean?

A diode is a two-terminal component in electronics with a unidirectional flow of current. It offers low resistance in the direction of current flow and offers high resistance in the opposite direction. Diodes are mostly used to prevent damage to components, especially due to electromotive force in circuits which are usually polarized.


Techopedia Explains Diode

The two terminals of a diode are polarized, with the positive end called an anode and the negative end called a cathode. The cathode is usually silver or has a color band. Control of current flow direction is one of the key features of diodes — the current in a diode flows from anode to cathode. The behavior of a diode is similar to the behavior of a check valve. One of the most important characteristics of a diode is the non-linear current voltage. If higher voltage is connected to the anode, then current flows from anode to cathode, and the process is known as forward bias. However, if the higher voltage is connected to the cathode, then the diode does not conduct electricity, and the process is called reverse bias.

There are different types of diodes such as normal diodes, light-emitting diodes, zener diodes, Schottky diodes and photodiodes. The circuit symbol of a standard diode is triangle with one corner against a vertical line.

Diodes have a wide range of applications, such as being used in:

  • Rectifiers
  • Switches
  • Signal modulators
  • Oscillators
  • Signal mixers
  • Signal limiters
  • Voltage regulators

Related Terms

Margaret Rouse
Senior Editor
Margaret Rouse
Senior Editor

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.