An Apple iPhone.
PHOTO: Justin Sullivan Getty Images
(USA TODAY) -- Arguably the most fascinating feature unveiled during Apple's iPhone event Tuesday is Touch ID, a fingerprint sensor included with the iPhone 5S.
With the device launching on Sept. 20, we answer 10 questions about the iPhone's latest feature.
1. What is it?
Touch ID is a fingerprint sensor that sits on the home button of the iPhone 5S.
2. What does it do?
It allows users to perform certain functions on the iPhone by simply placing their thumb or finger on the home button.
3. How will I use it?
Touch ID can replace the "slide to unlock" feature as well as numeric passcodes to access your phone. You can also make purchases on iTunes, the App Store or iBooks with just your fingerprint.
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4. Will it work with apps?
Third-party app developers will not have access to Touch ID. For now, users will only see compatible apps from Apple.
5. How does it read my fingerprint?
To set it up, iPhone owners will place and hold their thumb or finger on the home button several times. Using a capacitive touch sensor, Touch ID will "take a high-resolution image of your fingerprint and intelligently analyze it to provide accurate readings from any angle," says Apple.
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6. Where is my fingerprint stored?
Apple says a user's fingerprint will be stored in a "Secure Enclave" on the smartphone's processing chip. It will never get stored on Apple servers or iCloud, the company says.
7. So if enabled, will I be the only one that can access my phone?
Nope. Touch ID allows for fingerprints from multiple people, although it's not clear how many people the feature will accommodate.
8. What if it has trouble reading my fingerprint?
Passcodes and the "slide to unlock" options will remain as backups if, for example, you're wearing gloves and can't access Touch ID.
9. What if I don't want to use it?
It's optional. You can still opt for numeric passwords to secure your device.
10. What makes the sensor so special?
Touch ID adds another layer of security for users seeking something beyond passcodes. If implemented properly, the fingerprint sensor could also open the door for expanded use of mobile payment services. However, with the NSA scandal potentially tarnishing the reputation of tech giants like Apple, it's tough to tell how many users will embrace fingerprint recognition.