Two-Factor Authentication (2FA) is an additional layer of security to protect user accounts from unauthorized access

 Two-Factor Authentication (2FA) is an additional layer of security that helps protect user accounts from unauthorized access. It requires not only a password and username but also something that only the user has on them, typically a piece of information that's sent to a device (like a smartphone) or generated by a physical token.

Here's how it generally works:

1. User Credentials: The user enters their username and password as usual.
2. Verification Code: After the initial login attempt, a unique verification code is sent to the user's registered device, usually via SMS, email, or through an authenticator app.
3. Entering the Code: The user then enters this code along with their password to complete the login process.
4. Access Granted: If the code is correct, access is granted to the user.

Even if someone has stolen a user's password, they still can't access the account without this additional verification code, which is time-sensitive and unique to each login attempt.

This method significantly enhances security by ensuring that even if one factor (like a password) is compromised, the attacker would still need the second factor (like the verification code) to gain access.