Most of us refer to it as two-factor authentication (2FA), but Google prefers the term two-step verification (2SV). Call it what you will, but Google will make it the default for all users, contributing to creation an additional level better safetys in Google accounts.
Google has had this option for quite some time, but we will soon see it as a default. At least all those who have properly configured accounts, such as was announced in The Keyword.
On Android Appliances, αυτή η προτροπή θα εμφανίζεται ή σαν ειδοποίηση ή σαν μια διεπαφή πλήρους οθόνης που μπορείτε να χρησιμοποιήσετε για επιβεβαίωση. Στο iOS, μπορείτε να χρησιμοποιήσετε κάποια εφαρμογή της Google που είναι εγκατεστημένη στο phone to confirm that it really is you.
If you have already locked your Google Accounts with 2FA or 2SV, then you will simply see Google asking you to confirm that it is you with a single click through a prompt.
In any case, the notification will tell you the device, location and time the attempt was made connections, so you can be sure everything is correct.
If you have not already done so, Google will do so: "We will soon start automatically registering 2SV users if their accounts are properly configured."
We do not know at this time how soon Google will be "soon".