Every iOS device has the ability to determine where in the world it is, using a framework called Core Location. iOS also includes the Map Kit framework, which lets you easily create a live interactive map that shows any locations you like, including, of course, the user’s location. In this chapter, we’ll work with both of these frameworks. Core Location can actually leverage three technologies to do this: GPS, cell ID location, and Wi-Fi Positioning Service (WPS). GPS provides the most accurate positioning of the three technologies, but it is not available on first-generation iPhones, iPod touches, or Wi-Fi-only iPads. In short, any device with at least a 3G data connection also contains a GPS unit. GPS reads microwave signals from multiple satellites to determine the current location.