Sign in with Apple’ will allow users to quickly sign-up and log into third-party websites and apps using your Apple ID. Apple claims that signing-in with Apple ID would protect users’ privacy by not disclosing their actual email addresses to the 3rd-party services and also limiting personal information to the minimum necessary data. The feature will soon be available as an API for developers who want to integrate the single-sign-on button on their apps and websites, allowing their users to easily sign in “without tracking”
Source: https://thehackernews.com/2019/06/apple-launches-privacy-focused-sign-in.html