Like most cellular telephones, the iPhone offers a silent/vibration mode that allows you to receive notifications without any noise. This is a useful feature that allows for notification of incoming calls, voicemails and text messages without disturbing those around you. Many people choose to use this feature at movies, meetings and other places where cell phone sounds and ringtones are inappropriate. Since you are still notified by the phone's vibration of incoming calls, voicemails and messages, you don't have to worry about being out of contact while your phone is in this mode.
Unlock your iPhone's screen by pressing the iPhone's Home button and sliding your finger as instructed across the screen.
Tap the "Settings" icon, and then select the "Sounds" option.
Press the box to the right of the word "Vibrate" under the "Silent" subsection to turn on the vibration option when the phone is in silent mode. If you do not wish to turn on the vibration feature, skip this step.
Find the small buttons located on the left-hand side of your phone. Slide the top button to the left. Your phone will vibrate to confirm that your phone has entered the silent/vibration mode. You will also see a symbol on your screen—a bell with a slash through it. This tells you the ringer sound is off.