iCloud is Apple's cloud storage and computing service that allows users to store and access data such as music, photos, documents, and app data across multiple Apple devices. It launched in 2011, building on Apple's previous cloud services. iCloud provides 5GB of free storage that can be upgraded, and syncs purchased media, files, device settings and backups across devices. It also offers services like Find My iPhone, Photo Stream, and iCloud Keychain. While offering integration with Apple devices, iCloud competes with other cloud services from Google, Microsoft, Dropbox and others.