Unlike Android, iOS does not allow users to directly install third-party apps. Only those apps that are signed by Apple can only be installed by the iOS users. The provisioning profile is a link between the Developer of the app (his Developer Account) and the Device on which it is being used. The provisioning profile is downloaded from the developer account and the entire bundle is code-signed by the iOS. A Development Provisioning Profile must be installed on each device on which the developer wishes to run his application. If the information in the provisioning profile doesn't match certain criteria, the app won't launch. A provisioning profile necessarily consists of: Development Certificates : These are for developers who want to test the app on a physical device while writing code Unique Device Identifiers:  the List of devices that the app can run on An App ID: It is a two-part string used to uniquely identify different apps from a single development team. A staple in Xamarin developer interview questions with answers, be prepared to answer this one using your hands-on experience. This is also one of the top interview questions to ask a Xamarin Developer.