http://www.techradar.com/news/windows-10-s-is-becoming-windows-10-s-mode

Changes are coming to the stripped-down, lightweight operating system Microsoft produces and which has up until now been known as Windows 10 S: it's getting a new name for a start, and will become Windows 10 S Mode in the not-too-distant future.

That's according to the Microsoft watchers at Thurrott and Neowin, who say the company wants to rebrand the software so it fits better into its portfolio of products. The new S Mode OS will soon be available on most versions of Windows, limiting users to apps downloaded through the Windows Store, with an unlock option available for the full version of the software.