iCloud Drive stores your documents—including your presentations, spreadsheets, and images—in iCloud, so you can access them from any of your devices set up with iCloud. iCloud Drive allows your apps to share documents so you can work on the same file across multiple apps.
You can use iCloud Drive on devices with iOS 8 or later, Mac computers with OS X Yosemite or later, PCs with iCloud for Windows 5, or on iCloud.com To access iCloud Drive, you must be signed in to iCloud with your Apple ID. iCloud Drive works with Pages, Numbers, Keynote, GarageBand, and some iCloud-enabled third-party apps. Storage limits are subject to your iCloud storage plan.
Note: iCloud Drive is automatically turned on for new accounts and users (iOS 8 or later).