When you turn on iCloud Photo Library, all the photos and videos you take with iPhone or iPad are automatically uploaded, so you can access them from your iPhone, iPad, iPod touch, Mac, and PC and on iCloud.com. By storing all your photos and videos safely in iCloud, you’ll have more space on your iPhone to take even more great shots. And iCloud Photo Sharing makes it easy to show off just the photos and videos you want to just the people you want to see them.
iCloud Photo Library helps you make the most of the space available by automatically storing the original full-resolution photos and videos in iCloud and leaving behind lightweight versions that are perfectly sized for each device. You’ll always have access to everything on your device, even if you’re offline. And thanks to next-generation photo and video compression technology, photos and videos with the same quality as before now take up half the space.