The document summarizes Nokia's Lumia series of smartphones. It describes the first Lumia phones released like the Nokia Lumia 610, and later models such as the Lumia 920, Lumia 1020, and an upcoming Lumia 1520 phablet. All Lumia phones run Microsoft's Windows Phone operating system. The Lumia series aimed to compete with Apple and Android devices and helped make Nokia a top Windows Phone manufacturer, releasing models with improved cameras, processors and wireless charging over time.