This document discusses iris recognition as a biometric method for human identification. It begins by defining biometrics and outlining the development of iris recognition from the 1980s to modern applications. The iris is described as a protected internal organ of the eye that is visible from a distance and contains unique patterns. Key points are that iris patterns are stable over a person's lifetime and have a very low probability of matching between two different people. The document then covers the major parts of an iris recognition system and both technical challenges and applications.