Structure Core and Structure Sensor are built for different purposes.
While the Structure Sensor is designed to be used on iOS products with a robust Structure SDK and many applications backing it. The Structure Sensor and related Structure SDK is specifically designed for scanning purposes giving the developer very high-level functionality.
The Structure Core is built for embedded solutions such as robotics, AR/VR, and autonomous drones. The Structure Core is designed with computer vision experts in mind who looking to unlock the raw potential of a sensor. The software development kit that is included with the Structure Core is focused on raw depth data and does not include high-level functionality, like 3d object scanning.