Creating an App ID
Xcode can now authenticate you as a developer with distribution privileges. But because distribution is controlled on a per-app basis, you must create a unique ID for your app.
An app ID has two elements:
A bundle seed ID. This is a ten-character string. It’s generated automatically by the iOS Provisioning Portal. You don’t need to type it into Xcode.
A bundle ID. This is a separate string you enter manually into the Provisioning Portal and—sometimes—into Xcode.
In this context, “bundle” means “all the files in your app collected into a distributable package.”
Understanding app IDs
When you set up Xcode for device testing, a bundle seed ID is created automatically. You can use this seed ID for all your apps. It’s valid for both development (on-device testing, for example) and distribution.
There’s no good reason to create further seed IDs. If your apps share the same seed ID, they can automatically share passwords and other “secret” details stored in a device’s keychain—a special secure folder on “disk” that holds sensitive information in an encrypted form.
The simple way to create a bundle ID is to name it with a single asterisk. This creates a wildcard ID. ...