Microsoft Windows Store for Business, also known as Private Store

The Microsoft Windows Store for Business, also known as Private Store, is a new feature in build 1607 that allows enterprise administrators the ability to publish for use only certain approved applications. Furthermore, the general Windows Store can be disabled via policy, so only Windows Store for Business is allowed to install UWP apps. Conceptually, the Windows Store for Business offering is akin to SCCM's application library offering.

There are some prerequisites to enable this functionality for the enterprise. The IT administrator needs Azure AD and Windows 10 to do the initial signup, administration, distribution of apps, and license management. For the full experience though, the employees themselves need Azure AD accounts as well. The requirements are listed and explained here: https://technet.microsoft.com/en-us/itpro/windows/manage/prerequisites-windows-store-for-business. But generally, they are:

• Employees need Azure AD accounts when they access Store for Business content from Windows-based devices
• If you use a management tool to distribute and manage online-licensed apps, all employees will need an Azure AD account

Blocking access to the Windows Store outright can be achieved using AppLocker, MDM, or the Group Policy Turn off Store application.