The primary biometric disciplines include:

• Fingerprint (optical, silicon, ultrasound, touchless)
• Facial recognition (optical and thermal)
• Voice recognition (not to be confused with speech recognition)
• Iris recognition
• Retina-scan
• Hand geometry
• Signature-scan
• Keystroke-scan
• Palm-scan (forensic use only)

Disciplines with reduced commercial viability or in exploratory stages include: