Sarah Perez of TechCrunch has assembled an excellent, in-depth walkthrough answering key questions about how Apple’s upcoming authentication service, Sign In with Apple, will work:

From a security perspective, Apple offers a better option for both users and developers alike compared with other social login systems which, in the past, have been afflicted by massive security and privacy breaches.

Apple’s system also ships with features that benefit iOS app developers — like built-in two-factor authentication support, anti-fraud detection and the ability to offer a one-touch, frictionless means of entry into their app, among other things.
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Despite the advantages to the system, the news left many wondering how the new Sign In with Apple button would work, in practice, at a more detailed level. We’ve tried to answer some of the more burning and common questions.

Perez addresses questions regarding what information a developer receives when a user chooses Sign In with Apple, whether it’s possible to use the authentication service on Android devices, when an app will and won’t be required to use Sign In with Apple, and more.

Despite some controversy regarding how strongly Apple is pushing this new secure login option, if it works as advertised, Sign In with Apple could be one of the upcoming OS features that has the biggest societal impact in the long run.