How to Change the Auto-Lock on Your iPhone
The Auto-lock feature on your iPhone allows you to set the amount of time that elapses before the iPhone automatically locks or turns off the display. Or, you can set Auto-lock so that the iPhone never locks automatically. Your Auto-lock choices are five minutes before turning off, four minutes before, and so on, all the way down to one minute.
To change the auto-lock settings, tap the Settings icon, then the General button. Tap on the Auto-Lock option and choose your preference.
Don’t worry if the iPhone is locked. You can still get calls and text messages and adjust the volume.

iPhone Glossary
FaceTime
Apple software that enables users with supported mobile devices to both see and hear each other during wireless conversations.

iPhone Glossary
iCal
Apple’s personal calendar application.

iPhone Glossary
iCloud
Apple’s wireless storage and synchronization service that keeps digital information updated automatically and wirelessly without user instigation.

iPhone Glossary
iOS 5
The operating system for mobile Apple devices released in June, 2011. With iOS 5, data updates and synchronization occur wirelessly through the iCloud.

iPhone Glossary
jailbreak
Altering an electronic device to remove default restrictions imposed by the manufacturer.

iPhone Glossary
Siri
A voice-controlled personal assistant application purchased by Apple and available exclusively on the iPhone 4S.