iCloud: My Photo Stream overview
How it works
You can take a photo with your iOS device, or import photos from your digital camera to your iPad or your Mac or Windows computer. iCloud automatically pushes copies of the photos over any available Wi-Fi or Ethernet connection to your other devices.
The photos appear in My Photo Stream on these devices:
On your Mac, in iPhoto or Aperture
On your iOS 7 device, in the Photos app
On your iOS 8 device, in the Photos app (when iCloud Photo Library beta is not turned on)
On your Apple TV, under iCloud Photos
On your Windows computer, in the Pictures Library
On your iOS 8.1 device (when iCloud Photo Library beta is turned on), your most recent photos are uploaded to iCloud and appear in All Photos in the Photos app.
To conserve storage space, My Photo Stream keeps only your latest 1000 photos on your iPhone, iPad, or iPod touch. On your Mac and Windows computers, every picture from your photo stream can be automatically downloaded and kept permanently.
You can also set up your Mac and Windows computers so your new photos appear in a My Photo Stream album. Your computer has more storage than your iOS device and can automatically import all photos from My Photo Stream to your photo library.
If you take photos with burst mode or image stabilization, only the photos you select as favorites when using burst mode, and the final composite image shot with image stabilization, are added to My Photo Stream. If you want all burst-mode photos uploaded to My Photo Stream and your iPhone has iOS 7.1 or later, go to Settings > iCloud > Photos (or Settings > Photos & Camera), then turn on Upload Burst Photos.