You can choose between Optimize Storage or Download and Keep Originals. The former will prioritize iCloud over local storage to save space, the latter will keep the original copy on the phone. iCloud Photo Library uses iCloud storage space. You can store any number of photos as long as you have the available space. Your photo library can now be accessed from the Photos app on your iPhone, iPad, or Mac. You can also access your photo library from a web browser by going to the Photos section of www. icloud. com.