The word biometric is from a combination of two words, namely; bio (human) and metric (measurement). In simple terms, it is all about measuring things about humans which make them different from other humans. Biometric identification is a technique that uses unique human characteristics to identify an individual. As opposed to passwords or key cards, the various biometrics are something a person is and so they are harder to spoof, share or break. The biometric that people are most familiar with is the fingerprint, but there are many other types of biometrics with their own strengths and weaknesses. In essence, biometrics is a complex, diverse field of science.