It categorizes your fingerprint as one of three basic types-arch, loop, or whorl. Touch ID then intelligently analyzes this information with a remarkable degree of detail and precision. The sensor uses advanced capacitive touch to take a high-resolution image from small sections of your fingerprint from the subepidermal layers of your skin. On iPhone and iPad, a steel ring surrounding the button detects your finger and tells Touch ID to start reading your fingerprint. This protects the sensor and acts as a lens to precisely focus it on your finger. The button is made from sapphire crystal-one of the clearest, hardest materials available.

The technology within Touch ID is some of the most advanced hardware and software that we've put into any device. Developers can also allow you to use Touch ID to sign into their apps. You can use it to authorize purchases from the iTunes Store, App Store, and Apple Books, as well as with Apple Pay. With just a touch of your finger, the sensor quickly reads your fingerprint and automatically unlocks your device. Using Touch ID on your iPhone, iPad, and Mac is an easy way to use your fingerprint instead of a password for many common operations. Much of our digital lives is stored on our Apple devices, and we recommend that you always use a passcode or password to help protect this important information and your privacy. Learn how Touch ID helps protect information on your iPhone, iPad, and Mac. However this should mean that new B and W and Bose speakers that support Docks will now have to use their own DAC's in their also.About Touch ID advanced security technology The new iPhone 5 and new players may get problems though now with the Lightning adapter port as it's full digital out with a DAC in the adapter itself and as some have pointed out, yes a DAC is not expensive but with what most charge for accessories, being Apple and what not, for $29 it is unwieldadly to believe that the DAC and implementation inside is even 'good' as it's just 'there'. Of course the amp is the largest limiting part of their sound in terms of the two DAC and amp. This doesnt mean anything until you realize that everyone has an iPod and that these come standard. So yes, even now Apple still subtly holds to their root claims or device usage where they put in a custom 'high end' Cirrus Logic Chip on their computers and portable devices with good intergration.

DAC and amp measurements from 4 to 4S were improved and what not. Like Steve posted, yes they are, they generally if not always improve every generation with better measurements and subjective praise with every generation.

Why get ipod touch instead of iphone