iCloud Photo Stream is a useful feature that is part of Apple’s cloud-storage system, iCloud. When enabled, photos taken on your iPad will automatically be uploaded to the iCloud server and downloaded to all your iCloud-enabled devices.
To turn Photo Stream on, you need an iCloud account. Navigate to Settings -> iCloud -> Photo Stream. At this screen, you will see a short description of Photo Stream, along with the toggle for the feature. Turn it on, and you are set.
Have fun with your iPad!