These N-Channel FETs can switch up to 60V and 30A in order to turn on and off high-power devices. Because of the way transistors operate, we are able to use a low voltage and current to control the switching. Specifically, because of the 2.5V threshold voltage of this particular N-Channel FET (FQP30N06L) we can control it directly from a microcontroller or SoC that runs 2.8-, 3.3-, or 5-volt logic.
The TO-220 package is great for working on a solderless breadboard, and it also dissipates heat very well. Having a very low Rds(on) (~0.009 Ohms depending on Vgs) it can dissipate up to 2W without a heatsink. However, the TO-220 package also has a hole to properly mount a heatsink if you need to dissipate more.