So far, we have only used location values (latitude and longitude) from the iOS device, which lets us know the user's position. iOS devices can also report the direction of the user's phone (very helpful for navigation apps). The Core Location framework supports two methods of determining direction, using magnetometer and the device GPS.
As discussed before, the direction in which an iOS device is pointing to is reported by the device magnetometer. This information is known as heading. The device GPS hardware reports the direction in which an iOS device is moving. This information is know as course.