Two-factor authentication also refers as two-step verification or 2FA is a security feature that you can enable on your account to prevent anyone from accessing your account.

If you enable this option, you will be asked for the authentication code after entering the login details.  You can use Google Authenticator or the Duo app for authentication code generation. 

Once logged in to the respective app, you can either scan the QR code or enter the code which will be shown above the QR code to verify your account.

For more detailed information about this, Please refer to the below link.
       -> How to Enable 2-Factor Authentication for SeekaHost Client area?