Windows 10 Enterprise E3 is the name of the lower-end of two different versions of Windows 10 Enterprise. Windows 10 Enterprise E5 is the new name of the Windows 10 Enterprise version that also will include Windows Defender Advanced Threat Protection, a new Microsoft service for detecting and responding to attacks.
Microsoft announced the renaming of Windows 10 Enterprise last week, and said the E3 and E5 versions will also be available as part of "Secure Productive Enterprise" bundles.
Secure Productive Enterprise E3 -- the bundle formerly named "Enterprise Cloud Suite" -- will include Windows 10 Enterprise E3, Office 365 E3, and Enterprise Mobility + Security E3. (Enterprise Mobility + Security is the bundle formerly known as Enterprise Mobility Suite, if you're still with me here.) There also will be a Secure Productive Enterprise E5 bundle, which will come with Windows 10 Enterprise E5, Office 365 E5, and Enterprise Mobility + Security E5.
Microsoft didn't announce pricing or availability timing for Windows 10 E5 today. I've asked whether this version (the one with Windows Defender Advanced Threat Protection) also will be out this fall. No word back so far.
Update: Microsoft isn't talking about Windows 10 E5 pricing or availability today, a spokesperson said. Microsoft officials also won't say whether or not Windows 10 E3 will be available on August 2, when the other versions of Windows 10 Anniversary Update will be available, or if it only will be available some time this fall.
Users who don't want to buy Windows 10 Enterprise as a subscription will still be able to get Windows 10 Enterprise E3 on a per device basis through Microsoft's regular licensing programs, officials said.
Last week when I asked, Microsoft execs wanted to make clear that the new Windows 10 Enterprise and Secure Productive Enterprise licensing options were not the rumored "Windows 365" subscription service many had feared, as they are for Windows 10 Enterprise, not consumer/home variants of the product. Officials emphasized that the new Windows 10 Enterprise subscription plans were a continuation of what Microsoft instituted in December 2014 when they launched Windows Software Assurance per user.