Apple unveiled new privacy features for its upcoming iOS operating system for iPhone and iPad (iOS 13) It took the wraps off of an authentication mechanism that will allow users to sign into third-party websites and apps using their Apple ID. This is similar to the near-ubiquitous Log in with Facebook function that lets people avoid creating new credentials for every website by using trusted social-media logins. In contrast, Apple s sign-in mechanism allows users to opt out of revealing their real e-mail address.
Source: https://threatpost.com/wwdc-2019-apple-facebook-privacy/145290/