Face ID is a biometric authentication feature developed by Apple that uses facial recognition to unlock devices, make payments, and access secure apps. It employs advanced technology, including a dot projector and infrared camera, to create a detailed 3D map of a user's face, ensuring high accuracy and security. This technology is designed to work in various lighting conditions and can adapt to changes in appearance, such as facial hair or glasses. Face ID enhances user convenience while maintaining robust security, making it a popular choice for iPhone and iPad users worldwide.