Front of iPhone

[iphonesawesome]

On my iPhone 4S there's a front facing camera, then the speaker, but what is that line above the speaker?

[Turboladdade]

Proximity sensor. You probably have a white model. It's on the black ones too, it's just harder to see.

[iphonesawesome]

Thank you so much this question has been killin me

[mplsgrl]

This I my first iPhone. What is this proximity sensor used for?

[Turboladdade]

It detects when your holding your phone close to your head so it shuts off the screen and you can't press buttons on accident. When you move the phone away from your head again the screen will come back on.

[Aude]

I see ... I'm always muting my iPhone 3!

[mplsgrl]

Oh duh thanks.