What is a bundle ID?
A bundle ID, or bundle identifier, is the unique name an app carries inside Apple's systems, written in reverse-domain style such as com.example.recipes. Apple uses it to tell apps apart on a device, in App Store Connect and in provisioning profiles. No two apps on the App Store share one.
More about Bundle ID
Once an app is on the App Store, its bundle ID can't change: a new bundle ID means a new app. It is separate from the name people see under the icon and on the store, which can change with any update.
Bundle ID with Borel
Borel gives your app a bundle ID of its own and sets the app up at Apple when you publish, so you never have to invent one or type it into Apple's website. The name people see on the App Store is set separately, in your app's Store listing in Borel.
Related terms
Make your iPhone app in Borel
Describe it in your own words. Borel writes it in Swift, builds it on its own Mac and puts it on your iPhone.