iCloud: iCloud account
The Apple ID email address and password you use to turn on and use iCloud features and to access the web apps on iCloud.com.
You can use the same Apple ID that you use with iCloud to access many Apple services, such as the Apple Online Store, the iTunes Store, the App Store, and the Mac App Store. When you’re asked to sign in using your Apple ID, enter the same email address and password you used to turn on iCloud.
You can find your iCloud account information in these places:
On your iOS device, go to Settings > iCloud.
On your Mac, choose Apple Menu > System Preferences, then click iCloud.
On your Windows 8.1 computer, go to the Start screen, click the down arrow in the lower-left corner, then click the iCloud app.
On your Windows 8 computer, go to the Start screen, then click the iCloud tile.
On your Windows 7 computer, choose Start menu > All Programs > iCloud > iCloud.