Apple iCloud is an online storage and syncing service for a wide range of data, including music, emails, photos, files, contacts, calendars and software.
In addition to storage and syncing, iCloud offers iOS device backup and is able to integrate directly with third-party apps for even greater functionality. In September 2014, Apple’s iCloud service came under scrutiny after intimate images of celebrities were stolen and leaked to the public. Experts warn that iCloud has a “fundamental security flaw”: The security measure called two-step verification can be bypassed using easily available software that allows access to iCloud back-ups.
Following the hack, Apple acknowledged that some of its accounts had been compromised and urged its customers to “always use a strong password and enable two-step verification.”
iCloud, unveiled in June 2011, is the fourth generation of online services provided by Apple, replacing MobileMe, Apple’s previous attempt at content syncing. Previous models also include .Mac and iTools, which met varying degrees of success.