A provisioning profile is a collection of digital entities that connects physical devices to authorized developer teams, allowing developers to test their apps on real devices before submission to the App Store. There are four types of provisioning profiles: development, distribution, ad-hoc, and in-house, each with its own set of capabilities and entitlements. A provisioning profile contains an app identifier, team information, capabilities, entitlements, certificates, and unique device identifiers, which must be registered and renewed periodically to maintain validity. Expiration and invalidation of profiles can lead to issues with code signing and app launch, highlighting the importance of regular maintenance and checking of provisioning profiles.