If you’ve ever opened your Photos app on your iPhone, you might see a ton of photos you don’t recognize. This is because all photos saved go to Photos, like those taken by your camera, those saved from Safari, photos sent and received from WhatsApp and other messenger applications.
Basically it can get confusing, but iOS 15 will help make things a bit more organized and give you better management over your photos. This is because in iOS 15, the Photos app will now tell you where your photos originate from. When you tap on the Info button on a photo, it will pull up additional information like where the photo was saved from, like in the images above which show that the photo in question was saved from Safari.
It will also show you additional information about the photo like the date and time it was saved to your Photos app, along with the location. This information is useful because as MacRumors points out, they act as identifying tags meaning that you can look for photos easier that way. So for example if you want to erase photos you saved from the web, you can search for it by using the “Safari” keyword and it should pull up all photos saved from the browser.