iCloud Photo Sharing, previously known as shared Photo Streams, come built- in to every iPhone, iPad, or iPod touch running iOS 8 or later. With iCloud Photo Sharing, you can easily share a collection of photos with friends or family. You can even choose to let them add to your album, which makes iCloud Photo Sharing a great way to collect shared memories. Members of a shared Photo Stream can also comment and like photos.

Once you create a shared Photo Stream and invite people, they'll get an invitation to join. Once they do, they'll receive updates and notifications from the Photos app whenever a member of that particular stream adds photos. The shared Photo Stream creator can even create an iCloud link which you can then share with folks that don't have iPhones, iPads, or Macs. They can simply click the link and be taken to iCloud Photo Sharing on the web.

If you own a Mac, all of your iCloud Photo Sharing albums also show up in iPhoto as well, which in early 2015, will be replaced with the Photos app for Mac. If you've been using shared Photo Streams prior to iOS 8, all of the ones you've already created or been invited to appear in the same tab of the Photos app and continue to function exactly the same way.