Biometric Attribute

Full Title or Meme

Biometrics are literally the measures of the biologic phenotype of a User.

Biometric Attributes are taken to be exclusively the measure of human characteristics like fingerprint, facial and behavior patterns.
The human characteristics are another factor that can be a part of Multi-factor Authentication.
So the human characteristics can be considered to be a Credential.
The measurements of the characteristic are compared against a template of the characteristics using some Assurance level to produce a Validated claim.

False positives
False negatives
Attacks against the sensor capabilities. Various movie and television plots have shown the attacks like taking someone's eyeball, or using a thin-film replica of a finger print to complete an Authentication which Authorizes access.