Recognition of human individuals

Recognition of human individuals involves physical recognition, such as visual, auditory, or behavior recognition.

Recognition of acquaintances
From nearby, a human individual is mainly recognized by his or her face; individuals with prosopagnosia are unable to recognize the faces of other people.

Other differences in appearance may also impede recognition:
 * usually most of the body is covered with clothing, which varies from day to day;
 * body parts other than the face that are uncovered, such as hands, are not as easy to use to tell people apart;
 * the arrangement of the hair also helps recognizing people, but, like clothing, a person may vary this, and it may also be covered by headgear.

People can also fairly well be recognized by voice. The combination of visual and auditive recognition is even more effective and often removes any doubts. From longer distances, people can be recognized by their body size and shape and their gait.

Recognition for commercial, security and legal reasons, including forensics

 * comparing the face with that on a passport photograph
 * fingerprints
 * DNA fingerprinting
 * Iris scan
 * Retina scan
 * other biometrics
 * signature