An App ID is a registered entry in your Apple Developer account that ties a Bundle ID to your Team ID and declares which capabilities the app uses. The full string Apple stores looks like TEAMID.com.example.app, with the Team ID prefix that distinguishes your com.example.app from another team's.
Explicit vs wildcard
- Explicit App ID
- Covers one exact Bundle ID, e.g.
com.example.app. Required for App Store, push notifications, App Groups, iCloud containers, Sign in with Apple, in-app purchases, and most other capabilities. - Wildcard App ID
- Covers a family of Bundle IDs, e.g.
com.example.*. Useful for development across many short-lived demo apps. Cannot enable push, in-app purchase, App Groups, or iCloud containers.
What changes about it
- Adding a capability (push, App Groups, HealthKit, etc.) updates the App ID, which invalidates every existing profile that references it. Profiles must be regenerated.
- Renaming the App ID's display name does not invalidate profiles.
- Changing the Team ID is not possible. You register a new App ID under the new team.