Windows 10 is a personal computer operating system developed by Microsoft as part of the Windows NT family of operating systems. Officially unveiled in September 2014 following a brief demo at Build 2014, the operating system reached general availability beginning on July 29, 2015.
The main goal of Windows 10 is to unify the Windows operating system across multiple Microsoft product families—including PCs, tablets, smartphones, embedded systems, and Xbox One, as well as new products such as Surface Hub and HoloLens—allowing these products to share what Microsoft described as a "universal" application architecture and Windows Store ecosystem. Expanding upon the Windows Runtime platform introduced by Windows 8, this architecture allows applications to be adapted for use between these platforms while sharing common code.
Windows 10 introduced revisions to the operating system's user interface, including the addition of a Start menu similar to Windows 7 but incorporating Windows 8's live tiles, a virtual desktop system, a notifications sidebar (replacing the charms bar on Windows 8/8.1), and the ability to adjust user interface behaviors based on available input devices—particularly on laplets. Windows 10 provides integration with additional Microsoft services, including the intelligent personal assistant Cortana, and Xbox Live. Windows 10 also introduced a new default web browser, Microsoft Edge, as well as integrated support for fingerprint and face recognition login, and new versions of DirectX and WDDM to improve the operating system's graphics capabilities for games.
Unlike previous versions of Windows, Windows 10 adopted a tiered approach to updates that Microsoft has described as a "service", and receive new features at no charge for the "supported lifetime" of the device it is installed on. The Home and Pro editions automatically receive all non-critical updates as they are released without the possibility of declining them, in addition to automatic driver updates. Unlike Home, Pro is able to defer updates for a limited time, but not ignore them completely. Enterprise editions are capable of using periodic, long-term support milestones to ensure stability, while the Windows Insider program enables beta testing of future updates. To encourage its adoption, Microsoft announced that during its first year of availability, Windows 10 would be made available free of charge to users of genuine copies of eligible editions of Windows 7 or Windows 8.1.