Whether you have the 5GB you get free when you sign up for an Apple ID, or pay a monthly subscription for more space, iCloud Drive is like having an external hard drive that’s accessed through the internet. But it’s so much more too.
When a document or file is on iCloud Drive, it’s synced with all your other Apple devices, so you can (for example) create a document on your Mac, leave. All you need is a computer, tablet or smartphone with an internet connection and a browser. And while nothing on the internet is invulnerable, iCloud Drive is very secure, with end–to–end encryption on for most of your data and in–transit and on–server encryption for Mail, Contacts and Calendar.
