It reduces the risk of hardware failure due to overheating.
The fins increase the area of the board and thus provide for greater heat transfer.
Aluminum heatsink for power transistor, FET, IC, LED power amplifier, Voltage Regulator, SCR, etc.

Note:
Use Screw to install the heatsink.
Please check the specification table and make sure that the size of the heatsink fits that of your component.