Microsoft Windows (or simplyWindows) is a metafamily ofgraphicaloperating systems developed, marketed, and sold byMicrosoft. It consists of several families of operating systems, each of which cater to a certain sector of the computing industry. Active Windows families includeWindows NT,Windows Embedded andWindows Phone; these may encompass subfamilies, e.g.Windows Embedded Compact (Windows CE) orWindows Server. Defunct Windows families includeWindows 9x andWindows Mobile.

(source:https://en.wikipedia.org/wiki/Microsoft_Windows)