Proximity Sensor?

[liamf1]

I still don't understand what a proximity sensor is... Or what its trying to do... Can someone explain please?

 

[pastafarian]

For the most part, the proximity sensor is used to disable and turn off the display when it is near your face in order to prevent your cheek from changing something while your in a call.

 

[liamf1]

I was so confused on this..
I kept wondering... What is it trying to sense that Im close to...
But anyways,
Thank you for answering
-Sincerely,
Liam-