Google Authenticator, Additional Protection To The Password

https://play.google.com/store/apps/details?id=com.google.android.apps.authenticator2&hl=en

This post I decided to write after my internet friend did reset on your iPhone, along with the settings and flew off two-step verification (2fa). Backup keys, he did, and access to the resource 2fa was closed. Correspondence week and decided to wait the issue.
Searching the internet, I found more such cases.
Proof:  https://www.reddit.com/r/Bitcoin/comments/52ug08/help_lost_all_accounts_on_google_authenticator/

Strongly recommend print or rewrite site authorization keys when added to 2fa, and store in a safe place. Restore access to Google release 2fa can only use these keys!.

Why do you need Google Authenticator?
This additional protection to your password to enter, for example, the crypto exchange. Password changes every 30 seconds, an Internet connection is not required, it is possible to enter a code via QR codes (I do not always get). For people especially troubling for the means you can use your smartphone is not connected to the Internet.

On the Exchange stores your e-money and 2fa required to install !!! Stay a little paranoid, any password if you are connected to the internet you can get. Protect your money. thank you.