Microsoft initially debuted Windows 10 S in May as a primarily education-focused version of Windows 10. However, at Ignite 2017 this week, Microsoft revealed that new Windows 10 S devices for the enterprise are coming later this year. As it turns out, Microsoft is also working on a special version of Windows 10 S for enterprise users as well.
As reported by Neowin, this new version, called Windows 10 Enterprise in S mode, will still be locked down to only install apps from the Windows Store. The main difference is that it will be based on Windows 10 Enterprise, whereas the standard version of Windows 10 S is based on Windows 10 Pro. Just like Windows 10 S users can upgrade to Pro, Enterprise in S mode users will be able to upgrade directly to Windows 10 Enterprise, should they choose.
Windows 10 Enterprise in S mode will be available in spring 2018. That means it won't be available in time for the launch of new Windows 10 S devices for commercial users later this year, so it seems they'll initially be available with the standard version of Windows 10 S.