You know those 'Sign in with Google' or 'Sign in with Facebook' icons. Well, Apple just announced its own version and it's sure to annoy both Facebook and Google.
That's because it doesn't track user behaviour - Apple is particularly trying to push its sensitivity to privacy at the moment in the light of recent indiscretions by Facebook and Google's policies of tailoring advertising to you, basically monetising your web use.
Sign in with Apple can even create a fake email address for you so you don't get spam and enables you to tailor what data you give to websites and apps - we believe it will enable you to have different email addresses for different apps should you wish. You can choose to show or hide your real email.
Naturally, everything is controlled with your Apple ID and Apple is releasing an API for developers to enable them to add the new sign-in to apps. And, naturally, it'll work alongside Face ID. This will make things very convenient for signing into stuff.
It'll be available in macOS, iOS (and, presumably, iPad OS) and via websites.