Photo Stream allows you to automatically upload images to iCloud and share them with family and friends. While you can control who has access to your Photo Stream albums, you may not want to share all the photos and screenshots on your device. You can disable Photo Stream by following these steps.
1. Open the Settings app from your Home screen
2. Tap the Photos & Camera tab
3. Tap the My Photo Stream toggle so it is white not green
You can also enable or disable the Photo Sharing and Summarize Photos features from this section.