Apple Announces iCloud

Apple announced iCloud at WWDC in June 2011 as a replacement for MobileMe and as a broader synchronization layer for its devices. The goal was to make data such as contacts, calendars, photos, documents, and purchases follow the user automatically.

Cloud synchronization sounds simple until two devices edit the same information while offline. A service has to identify versions, resolve conflicts, retry failed transfers, and avoid silently overwriting newer data. Apple also introduced iTunes in the Cloud and Photo Stream, moving more media management away from manually syncing through a cable.

The announcement reflected a larger change in personal computing. The PC was no longer assumed to be the single master copy of a user’s digital life. Phones, tablets, and computers increasingly became peers connected through a cloud account.