In one sentence: Biometrics are body features, such as your fingerprint or face, that a device uses to check it is really you.
Why it matters: They let you unlock a phone or approve a sign-in quickly. Apple says that Face ID data does not leave your device, and Google says the same for biometric data used with passkeys. Always set a passcode or PIN as well, because your device asks for it as a backup.
One thing to do: Check that your phone has a passcode or PIN that is hard to guess.
Related terms: passkey, security key, privacy settings
Learn more: The 30-Minute Account Clean-Up
Checked: 25 Oct 2026. Settings screens change. If yours looks different, search the company's help page.
