As one of the core apps comes pre-installed with iOS, the Photos app allows iPhone users to edit and manage their iPhone photos easily and conveniently. Unfortunately, some iPhone users get confused about why some albums can be deleted while others cannot. Now I am going to figure out why some photo albums cannot be deleted together with you.
Photo albums you created by yourself
You can create albums and name it whatever you like, and add whatever photos you like on your iPhone or iPad. And these self-defined albums can be deleted whenever you’d like. However deleting the album will not delete the photos in the album from your iPhone or iPad. The photos themselves will remain in collections, other albums, and in Photo Stream.
This is because your photos are actually stored in only one album – the Camera Roll Album. Even if you add a photo to another album, there is actually only one copy of that image on your iPhone. So if you want to delete some specific image, you have to delete from your Camera Roll.
Photo albums defined by iOS
Now, the phone will automatically detect pictures that fall into different types as the latest iOS 9 has been released. iPhone stores some kinds of photo away in their own folder – time-lapse, slo-mo, burst photos and videos all get their own album, and now screenshots and selfies with iOS 9. These albums currently can't be deleted by the user.
Photo albums synced from a Mac or PC
Albums including photos synced from you Mac or PC through iTunes cannot be deleted directly from your iPhone. If you want to delete them, or specific photos within them, you'll need to go through iTunes again. For example, if you want to delete certain photos from an album, you'll need to delete them from the album on your computer and then apply sync changes in iTunes. If you want to remove an entire album, just uncheck it in iTunes and sync again.
Photo albums created by third party apps
Some albums created by third party apps from App Store seem to give users trouble when it comes to managing them. Some of them have a way to disable this functionality, while others don't. For example, Snapseed by default will create its own album in the Photos app and store any photos you've edited and saved. While convenient for some, it may be annoying for others. You can go into Settings > Snapseed in order to disable this behavior. Other apps offer a disable toggle as well so be sure to check the Settings app for it.
One thing you have to keep in mind is that albums are simply a way of organizing your photos into different sets to make it easier to find and view just the photos that you want to look at. Deleting photos from an album does not mean deleting the photos from your iPhone, instead, it only means that you remove the photos from the album you previously placed it. If you want to delete specific photos from your iPhone, delete it from your Camera Roll.