Relay [ intro ]

relays are the simplest and important components, a relay is not only a simple switch in a circuit it also acts as a bridge between low powered devices and high powered devices, simple example in microcontrollers use relays to control AC using a DC signal.
basically really consists of a coil which builds up a magnetic filed when current is passed through it, and that causes to open a switch or close it,
using this magnatic field to pull a conduct material to close the circuit or to release the same conduct material to open the ciruit!!

Definition:

A relay is an electrically operated switch. Many relays use an electromagnet to mechanically operate a switch, but other operating principles are also used, such as solid-state relays.

Most Common Types of relays:

1. Electromagnetic Relays
   
2. Solid State Relays
   
3. Hybrid Relay
   
4. Thermal Relay
   
5. Reed Relay