If you know something about electronics you will know a little about this important electronic part called triac. Triacs are basically one of the active members of the electronic component family used for switching applications.
Switching application refers to the making and breaking of a particular load that might be connected with the component. In other words, a triac functions quite like the mechanical switch that we normally employ for switching our domestic load ON or OFF.
If you take a triac, it will have the following appearance, let's understand what is a triac:
It is a black colored part,
The hind portion of the triac is fitted with a metal plate while the front consists of the number and other related specs of the device.
The back metal plate also carries a small hole at the top, which an be used for screwing an external metal which may act like an heatsink if the device is controlling high load currents and tends to heat up.