But sometimes things can go wrong, and if your iPhone is unresponsive - and all other troubleshooting steps have not solved the problem - then you might need to enter recovery mode. To be clear ...

Let go of the button and the device will start up. How to Put an iPhone Into Recovery Mode Recovery Mode is a last-resort ...

6. Keep holding Volume Down (or Home) until iTunes on your computer says "iTunes has detected an iPhone in recovery mode. You must restore this iPhone before it can be used with iTunes." ...