The Samsung Galaxy S6 allows you to unlock your device using your fingerprints instead of using the conventional password or lock pattern mechanism. This is achieved through the use of a FingerPrint Sensor built into the Home button of the S6. This procedure explains how to enable this feature your S6 and also how to register your fingerprints:
Go to Apps > Settings > Lock screen and security. Tap on Screen Lock Type > Fingerprints:
Follow the onscreen instruction to register your fingerprint:
At the end of the procedure you will be asked to create a backup password to unlock your phone when fingerprint recognition is not available:
At this point you can register another fingerprint, by going to the Security section > Fingerprints > Add fingerprint: