MacMost Now 628: Understanding the iPhone Photo Library
When you sync photos from your computer to your iPhone you will get an album named Photo Library in your Photos app. This isn't an album, but a complete list of all of the synced photos on your iPhone. It will include those in albums and events you have synced, but the photos are really only on your iPhone once. The Photo Library is just a way to view of list of all of these photos instead of viewing them by album or event.