Difference between Diode and Rectifier

Key Difference: A diode is a type of electrical device that allows the current to move through it in only one direction. It consists of an N-type semiconductor and a P-type semiconductor that are placed together. Rectifiers are electronic devices that are used for converting AC voltage into unidirectional pulsating DC voltage. Diodes are often used in the design of rectifiers.

A diode is one of the simplest nonlinear circuit elements. It can be compared to a resistor as it also possesses two terminals. However, it has nonlinear current voltage characteristics. A diode can be described as an electronic component that tends to permit current flow in one direction. In addition to this, it also inhibits the current flow in the opposite direction. In other words, it is the simplest two terminal unilateral semiconductor devices. The two terminals of the diodes are known as anode and cathode. It consists of an N-type semiconductor and a P-type semiconductor that are placed together. The Cathode is the P-Type side, and Anode is the N-Type. A diode can be closely related to a switch. One of the most common types of diode is the ‘silicon diode’. It is enclosed in a glass cylinder and also contains a dark band that marks the cathode terminal.

An arrow like circuit symbol is used to represent the direction of conducting current. Other important characteristics of diodes include – forward biasing voltage makes it turn on. On the other hand, reverse biasing voltage makes it turn off.

Rectifiers are electronic devices that are used for converting AC voltage into unidirectional pulsating DC voltage. Rectifiers can be made from various components like solid state diodes, vacuum tube diodes, mercury arc valves, and other components. A device that works just opposite to a rectifier is also known as an inverter. A simple rectifier circuit can be constructed by using a single diode which is inserted into one of two AC lines before the load. The process is termed as rectification.

A rectifier diode allows electrical current to flow through it in only one direction and is therefore mainly used for power supply operation. Rectifier diodes are specific types of diodes that can handle higher current flow than regular diodes.

Comparison between Diode and Rectifier:

	Diode	Rectifier
Definition	A diode is a type of electrical device that allows the current to move through it in only one direction.	Rectifiers are electronic devices that are used for converting AC voltage into unidirectional pulsating DC voltage. Diodes are often used in the design of rectifiers.
Uses	Clipping and Clamping - to protect the circuits by putting limitations on the voltage Voltage rectifier – Turing AC into DC Voltage Multipliers Non-linear mixing of two voltages	They can be found regulating the power in computers and the electrical power in motor vehicles. They can also be used in battery chargers for rechargeable batteries, computer power supplies and vehicle batteries. Often used for AC to DC conversion, Can also be used in the detector of radios in order to perform radio demodulation.
Types	Junction diode (ordinary type) Light emitting (LED) Photodiodes (absorbs light, gives current) Schottky (high speed switch, low turn on voltage, Al. on Silicon) Tunnel (I vs. V slightly different than jd's, negative resistance!) Veractor (junction cap. varies with voltage) Zener (special junction diode, use reversed biased)	Half-wave rectifier - It is the simplest type of rectifier, which is made with just one diode. Full-wave rectifier - This rectifier is essentially made of two half-wave rectifiers, and can be made with two diodes and an earthed center tap on the transformer. Bridge rectifier - It makes use of four diodes in a bridge arrangement to achieve full-wave rectification.
Device Type	A diode only has 2 semi conductive regions, and therefore has 2 leads.	A rectifier assembly generally has multiple diodes, or more than two terminations.