What do I need iCloud storage for?
How do I use iCloud storage
Mac Pro
Hello,
Apple devices work along with Apple Cloud service called iCloud.
iCloud is used by various apps on your iPhone, iPad, iPod and Mac among other devices. For example: Photos, is an app available across multiple Apple devices where the photos you have taken can be stored physically on the device you have used to take photo or store it in iCloud, so that if you loose the device, you can download from the iCloud. Having said that iCloud is not to be confused to a storage medium for most items, it is a syncing medium primarily. What that means is: if you delete and item that is stored on iCloud, it will be removed from you device as well.
Hope it helps.