Windows Phone is the Microsoft Operating System (OS) for smartphones and tablets. Windows Phone is mostly dedicated to individuals but a specific corporate area was launched end 2010. Windows Phone mobile applications are developed in a software environment coming from Visual Studio, with a dedicated Software Development Kit (SDK).

Windows Phone and its large number of versions is directly in competition with iPhone iOS, BlackBerry OS and Android, the Google mobile OS; In Q1 2013, Windows Phone became the third Operating System, and is consolidating its third place in 2013 with 3.3% (+0.9pp) of the global market share.

At the end of 2011, Nokia has announced a strategic partnership with Microsoft to equip the coming generations of Nokia smartphones with Windows Phone as Operating System.

Windows Store is the application store for the Windows Phone applications and there is at the end of 2013 more than 200,000 applications, but Windows Store is still far behind Android and iOS application stores (more than 1 million applications for each of them).