iCloud is a cloud service developed by Apple Inc. that was launched on October 12, 2011. It is built into iOS, iPadOS, watchOS, tvOS, and macOS, and can also be accessed through a limited web interface and Windows application. 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 also includes a free email account and 5 GB of free storage for your data. Users can subscribe to iCloud+ for additional storage up to 2 TB (or 4 TB for users of Apple One Premier plan who also buy an additional 2 TB of storage) . Some of iClouds features are accessible not only through apps built into iOS, iPadOS, watchOS, tvOS, and macOS but also on iCloud.com. iCloud Drive is iClouds file hosting service that syncs files across devices running iOS 8, OS X Yosemite (version 10.10), or Windows 7 or later, plus online web app access via iCloud.com. iCloud+ is a paid upgrade that becomes available once you update to iOS 15 or iPadOS 15, and includes tiers of 50GB, 200GB, and 2TB of iCloud storage, plus several enhanced features that are not accessible through the free 5GB plan.