How does Apple's two-factor authentication work?

Episode 1457 (53:17)

Ed from Clairemont, OK
Apple Two-Factor Authentication

Ed set up two-factor authentication on his Mac. But it when he logs into his Apple account, it sends the two-factor authentication code to his Mac. How can that be secure? Leo says it isn't. Apple's idea of two-factor authentication is kind of interesting. The argument is, if he has the password, and he controls the hardware the two-factor code is sent to, then there's a good chance that he is who he says he is. But it would be much better to send it to the smartphone.

Ed also wants to know why his GPS location isn't where he is. Leo says that's likely because Ed's computer doesn't support GPS, so it maps to his nearest ISP IP address.