Fingerprint. Computer artwork of a fingerprint residue showing typical patterns for feature identification (whorl, ridge ending and bifurcation). A fingerprint is a water and oil pattern imprinted by the ridges on the skin of the finger. These ridges form a distinct pattern, with each fingerprint being unique to an individual. Even identical twins have different fingerprints. They are therefore useful as a physiological biometric characteristic, where biometrics is the identification of people by their body parts.