This small module is a breakout board on which there is a MOSFET IRF520 that works as a Switch, with it it is possible to replace for example the use of a relay.
The module is designed to switch DC powered loads. Management is possible via a single digital pin of the microcontroller. Other possible examples of use are to drive a DC motor for robotic applications, or to control other loads, always in direct current.
For more information see the page of my site