In the pList file, there is a bundle ID of the form com.mycompany.myapp, but Apple also provides an app ID on the developer portal.
Thus, basically, what is the use
Simply, A bundle ID precisely identifies a single app. A bundle ID is used during the development process to provision devices and by the operating system when the app is distributed to customers.
During the development process, you use an app’s bundle ID in many different places to identify the app.
Whereas, An App ID is a two-part string used to identify one or more apps from a single development team.
The Team ID is supplied by Apple and is unique to a specific development team, while the bundle ID search string is supplied by you to match either the bundle ID of a single app or a set of bundle IDs for a group of your apps.
There are two types of App IDs: an explicit App ID, used for a single app, and wildcard App IDs, used for a set of apps.
sources: Bundle ID , APP ID