ICloud

iCloud is a personal cloud service run by Apple. Launched on October 12, 2011, iCloud enables users to store and sync data across devices, including Apple Mail, Apple Calendar, Apple Photos, Apple Notes, contacts, settings, backups, and files, to collaborate with other users, and track assets through Find My. iCloud's client app is built into iOS, iPadOS, watchOS, tvOS, macOS, and visionOS, and is available for Microsoft Windows. iCloud may additionally be accessed through a limited web interface. iCloud offers users 5 GB of free storage which may be upgraded through optional paid plans to up to 12 TB; all paid plans include iCloud+ providing additional features. Optional end-to-end encryption has been available since 2022 for all iCloud data, except Calendar, Contacts, and Mail, which rely on legacy sync technologies for compatibility with third-party apps (CalDAV, CardDAV, IMAP). As of 2018, the service had an estimated 850 million users, up from 782 million users in 2016.