Silencer Switch, Volume Keys
Praise be to the gods of technology—this phone has a Silence All switch!
This little flipper, on the left edge at the top, means that no ringer or alert sound will humiliate you in a meeting, a movie, or church. When you move the switch toward the front of the iPhone, the ringer is on. When you push it toward the back, exposing the orange dot, the ringer is off.
Tip
Even when silenced, the iPhone still makes noise if you've explicitly set an alarm, as described Alarm.
Also, the phone still vibrates when the silencer is engaged, although you can turn this feature off; in Sounds.

No menus, no holding down keys, just instant silence. All cellphones should have this feature.
Tip
With practice, you can learn to tell if the ringer is on while the iPhone is still in your pocket. That's because when the ringer is on, the switch falls in a straight line with the volume keys. By swiping your thumb across these controls from front to back, you can feel whether the silencer switch is lined up or tilted away.
Below the silencer, still on the left edge, is the volume control—an up/down rocker switch. It works three different ways:
On a call, these buttons adjust the speaker or earbud volume.
When you're listening to music, they adjust the playback volume.
At all other times, they adjust the volume of sound effects like the ringer and alarms.
Either way, a corresponding volume graphic ...
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