Biometric authentication is a method of identifying online users based on the unique physical features of the user, such as their fingerprint, facial features, or voice. It is considered to be a secure method for logging into accounts since the user's identity is uniquely verified via their biometric data.

To ensure a secure method of logging in to accounts, it is important to take the following steps:

1. Use a strong passphrase or multi-factor authentication like one-time passwords.
2. Use secure and encrypted connections when accessing accounts and services.
3. Enable auto-lock feature on all devices.
4. Monitor account activity regularly.
5. Update software and passwords frequently.
6. Be mindful of phishing attempts.