The document discusses the AssetsLibrary framework in iOS 5 which allows accessing and modifying photos and videos that are stored in the users photo library. Key points include: - The AssetsLibrary framework provides APIs for browsing, loading, and saving images and asset metadata. - Assets are organized into groups and can be represented using ALAsset and ALAssetRepresentation classes. - iOS 5 adds capabilities for editing asset metadata like date and location as well as writing modified image data back to the photo library. - Notifications are provided when changes are made to the photo library through other applications or services.