Help:Two-factor authentication - Wikipedia
https://en.wikipedia.org/wiki/Help:Two-factor_authentication
Two-factor authentication (2FA) is a way to add additional security to your account. The first "factor" is your usual password that is standard for any account. The second "factor" is a verification code...
Two-factor authentication - Passport. Help
https://yandex.com/support/passport/authorization/twofa.html
Two-factor authentication. You can set up your Yandex account so that you can only log in to it using This mechanism is called two-factor authentication (2FA), and it provides your account with a higher...
2FA Authenticator App (2FAS)
https://2fas.com/
Two Factor Authentication. 2FA doubles the account's security by requiring a regular password and a Time-based One-time Password (TOTP). 2FAS App generates TOTP on the user's device.
What Is Two-Factor Authentication (2FA)? - Authy
https://authy.com/what-is-2fa/
Two Factor Authentication, or 2FA, is an extra layer of protection used to ensure the security of online accounts beyond just a username and password.
What is two-factor authentication and how... | Facebook Help Center
https://www.facebook.com/help/148233965247823
Two-factor authentication is a security feature that helps protect your Facebook account.