Apple introduced an additional layer of security for iPhone, iPad and Mac users a few years ago by rolling out two-step verification for Apple ID accounts. Two-step verification prevents anyone from accessing an Apple ID account, even if they know the password, by requiring a four-digit verification code sent via SMS or Find My iPhone. When you enable two-step verification, you must register at least one trusted device capable of receiving SMS text messages.
Once activated, two-step authentication is required when managing your Apple ID through My Apple ID, signing into iCloud, or making iTunes, iBooks or App Store purchases from a new device. Apple has also expanded two-step authentication to iMessage and FaceTime, requiring users to input an authentication code from a verified device on accounts that have two-factor verification enabled to prevent unauthorized entry attempts through both services.
Overview
[youtube https://www.youtube.com/watch?v=9jXp1Supt7U&w=640&h=360]
Steps to Enable Two-Step Verification
Final Words
To ensure continued access to your Apple ID account after enabling two-step verification, it is essential that you record your recovery key in a safe place. Losing your two-factor recovery key could permanently lock you out of your Apple ID account, especially in the event you are being hacked. Without the recovery key, you will be forced to create a new Apple ID.
Two-step verification may provide an additional layer of security, but it is still highly recommended that you set a secure password for your Apple ID account. Avoid using common names, phrases or dictionary words in your password, and try to use as many lowercase and uppercase letters, numbers and symbols as possible.