Once it’s fully functional, iCloud Photo Library will give you online access to your entire digital image library from all of your computers and iOS mobile devices, as long as Internet access is available. As a result, you’ll theoretically be able to conserve internal storage space within your device by storing the majority of your photo collection online. By doing this, however, images that are not stored within your device will only be accessible when your device has Internet access.
The ability to share only the images you want with the specific people you choose is a nice feature, especially since you can grant different people access to your specific Albums. For example, if you grant a friend access to an Album containing images from a birthday celebration, that person will not also have access to any of your other Albums unless you specifically give it to them. Plus, at anytime, you can retract permission for someone to access your Album(s). This can all be done from within the Photos app on your mobile device, Mac or iCloud.com.
Once iCloud Photo Library is fully implemented and integrated within iOS 8, OS X Yosemite, the Photos app running on iOS mobile devices and Macs, as well as by third-party apps, there’s no doubt that Apple will greatly expand the functionality offered by this feature, and that it will evolve over time.
Ultimately, iCloud Photo Library will be one feature that people who enjoy taking and sharing pictures will come to really appreciate, especially when they realize how much time and effort they’ll save keeping their images up-to-date and synced between all of their computers and mobile devices.