An Apple ID isn’t just for downloading apps. A lot of features on both iOS and macOS are tied to an Apple ID e.g., iCloud, Calendar, Messages, etc. Some of these features are closed off so that you can only use them from an Apple device but others can, and do work with third-party apps e.g. Calendar or iCal. You can add your iCal events/appointments etc to any other app such as Outlook but in order to do that, you will have to sign in with your Apple ID in Outlook.
This is simple enough to do but if you don’t trust other apps with your Apple ID, or you’re worried the app might store the password, you can use app-specific passwords instead.
Create app-specific passwords
In order to create an app specific password, you need to first make sure you have two factor authentication enabled for your Apple ID. Without it, you will not be able to create app-specific passwords.
Once you’ve enabled two factor authentication for your Apple ID, visit this page. Sign in with your Apple ID and then scroll down to the Security section. Click ‘Generate Password’ under ‘App-Specific Passwords’.
A pop up will open asking to first enter a label for the password that you’re generating. It’s best to enter the name of the app, or service, that you intend to use the password for. It will allow you to revoke them more easily in the future if you need to.
After you give it a label, a password will be generated. Use the password to sign into whichever app is asking to sign in with your Apple ID.
If you ever need to revoke an app or service’s access to your Apple ID, you should first sign out of it. After that, you should revoke the password that was generated. To do this, visit the same page as before. Scroll down to the Security section and click the Edit button at the top right of it.
Next to App-specific passwords, you will see an option to View History. Click it. A pop-up will open listing all the labels that a password was generated for. You won’t see the password itself however, you will see the date it was created on. Click the close button next to a label to delete it, or click the Revoke all button to revoke all app-specific passwords.
Apple has always been very good with security. Google has its authenticator app but Apple doesn’t rely on it or other similar solutions. Instead, it has its own method for keeping passwords and user data safe.