The 2ndfactor is an online account security system. Generate a time-limited code with your iPhone to log into your favorite websites and protect them from unauthorized access.
Do you use similar username and password combinations for each of your sensitive Internet accounts?

It only takes one of those websites to suffer a security breach and your sensitive account credentials will be in the hands of a hacker for all of the websites you use. If this username and password combination is the same as your email address the hacker can now reset your passwords on your behalf locking you out of your own accounts!

Enabling the 2ndfactor on your accounts means that to log in you need a time-limited code generated by your phone. So even if a hacker steals your username and password without the generated code from your iPhone they will not be able to access your accounts.