Biometrics are part of the cutting edge of technology. Put simply, biometrics are any metrics related to human features. Fingerprinting is a very early and simple version of biometrics, like when you login to your phone using your fingerprint. As with any emerging technology, the first question you should ask is if they are safe.
How Do Biometrics Work?
If you've ever put your fingerprint into an device, you have a vague idea of how biometrics work. Basically, you record your biometric information, in this case a fingerprint. The information is then stored, to be accessed later for comparison with "live" information. Anyone else in the world can put their finger on you device's touch circle and it's not going to open your phone.