iCloud

iCloud is a cloud service operated by Apple Inc. that allows users to store and sync data across devices, including Apple Mail, Calendar, Photos, Notes, contacts, settings, backups, and files. It offers 5 GB of free storage, which can be upgraded to up to 12 TB through optional paid plans, and provides additional features such as Private Relay, Hide My Email, and Custom Email Domain through its iCloud+ service. As of 2018, iCloud had an estimated 850 million users, with 20 million users signing up within a week after its launch in 2011.learn more on wikipedia