In iOS 4, it appears that Apple will be giving users the ability to add captions to their photos. This means that in addition to whatever other information that is related to the photo, like the time, date, and location, users will also be able to add captions to make it more contextual and to make it easier for them to know what’s going on when browsing through older images.
These captions also means that users will be able to search for specific photos based on the captions that they’ve added, which you could also think of as being similar to tags. Prior to this inclusion, the only way for users to add captions to photos was to use the Photos app on their Mac computers through the Description field.
However, with this change, Apple has also updated the Photos app on macOS Big Sur where the Description field has been renamed to “Captions”. If you have enabled syncing, then captions added to photos in iOS 14 will also show up in the Captions field in Photos on macOS Big Sur, and vice versa.