Yes correct. it is being used as a finger scanner.
Touch ID is a fingerprint recognition feature, designed and released by Apple Inc., and currently available on the iPhone 5S, the iPhone 6 and iPhone 6 Plus, the iPad Air 2, and the iPad Mini 3. Apple says Touch ID is heavily integrated into iOS devices, allowing users to unlock their device, as well as make purchases in the various Apple digital media stores (iTunes Store, the App Store, iBookstore), and to authenticate Apple Pay online or in apps. On announcing the feature, Apple made it clear that the fingerprint information is stored locally in a secure location on the Apple A7 (in iPhone 5S and iPad mini 3 (APL0698)), A8 (in iPhone 6 and iPhone 6 Plus), or A8X (in iPad Air 2) chip, rather than being stored remotely on Apple servers or in iCloud, making it very difficult for external access.
