Set Up iCloud Photo Library
In true Apple fashion, turning on iCloud Photo Library is almost a one-click operation. Here’s how to enable it in Photos for OS X and Photos for iOS, plus the settings you need to be aware of to make it work well.
Photos for OS X
To get iCloud Photo Library working on your Mac, do the following:
First, you need to be signed in to iCloud. If you’re not already, open System Preferences, click the iCloud icon, and enter your Apple ID and password. You can also reach the same point from the preferences window in the Photos application, under iCloud.
In Photos, go to the iCloud preferences window and click the iCloud Photo Library checkbox (4.4). Once it’s enabled, Photos begins uploading the contents of your library to iCloud.
4.4 Enable iCloud Photo Library.
Choose how to store the image files on the machine:
Download Originals to this Mac: The original files are stored locally as well as in the cloud.
Optimize Mac Storage: The original files are kept in the cloud, and if space permits, originals remain on the Mac. However, most photos stored on the computer are compressed, low-resolution versions.
Photos for iOS
The steps to enable iCloud Photo Library on an iOS device are nearly identical:
Open the Settings app.
Tap the iCloud setting and sign in using your Apple ID and password (the same ones you use on the Mac).
Tap the switch for iCloud Photo Library to turn it on (4.5).
4.5 Enable iCloud Photo Library on an iPhone.
Choose whether originals or optimized versions of photos should be stored on the device (see step 3, above).