Synced content on an iPhone refers to the content that is synchronized or transferred between the iPhone and a computer using the Finder or iTunes. This content can include music, movies, TV shows, podcasts, photos, contacts, and calendars. Syncing with the Finder or iTunes keeps supported content up to date between the iPhone and computer. For example, when you add a movie to your iPhone, it also appears on your computer. After setting up syncing between devices with a cable, you can set them to sync wirelessly and automatically whenever they’re connected to the same Wi-Fi network. The synced content can occupy storage on the iPhone, and it appears as a category called "Synced Content" in the iPhone storage.