Abstraction of location services (GPS/Geofencing etc.) providing user global positioning and monitoring over such changes both in the foreground and background.

Trivial one time usage of location data can look like this sample:

You can also track location in the foreground using API calls like this:

Geofencing allows tracking whether a user entered a specific region, this can work when the app is completely in the background and is very efficient in terms of battery life: