A CoreLocation developer specializes in using Apple's Core Location framework to create location-aware applications for iOS devices. They use GPS, Wi-Fi, and cellular data to determine the geographic location, tracking the device's movement and updating locations in real time. They also handle permissions, ensuring only authorized apps can access location data. Their work enables features like geofencing, which triggers actions when a device enters or leaves specific locations, and beacon ranging, which determines proximity to Bluetooth beacons. They work closely with other developers to integrate these functions into apps, enhancing user experience with personalized, location-based services.