While I’ll leave it to my more enterprise-focused compatriots at Windows IT Pro to dig deep on the mainstream Windows Server 2012 versions (Standard and Datacenter), I’m more concerned with the lower end of the market: small businesses and home offices. With previous Windows Server versions, Microsoft served this market segment with a bewildering range of product offerings. But this time around, there are just two: Windows Server 2012 Essentials and Foundation. The question is, Which makes the most sense for you?

Spoiler alert: I’ve chosen the simpler Windows Server 2012 Essentials for my own home office setup.  But I’ve gotten some questions from readers about the semi-related Foundation edition: What are the differences? And why might an organization choose one over the other?

I’ll specify what I view as the most important differences -- as well as some of the similarities -- in just a moment. But what it boils down to, I think, is this: Whereas Essentials is aimed at organizations with absolutely no IT staff at all, Foundation assumes at least some in-company IT. (See also, "Introducing Windows Server 2012").

That distinction alone doesn’t justify an entire article, however -- so let’s dive a bit deeper.

Licensing. Whereas both Essentials and Foundation are typically acquired as part of a new low-end server purchase, this is in fact the only way you can acquire Foundation. But enthusiasts or home users will be able to purchase Essentials at retail for about $425 and install it on their own hardware, and OEM and volume licensing versions will also be available. In my tests, Essentials works fine with any Windows 7- or Windows 8-compatible PCs, so this is an interesting choice for those looking to repurpose a previous PC when they upgrade. (See also, "Q: What are the versions of Windows Server 2012 and how do they differ?").

Availability. Foundation shipped in September with Standard and Datacenter, although availability is of course limited by the PC/server makers that provide it to customers. Essentials will RTM by the end of the year, although the near-final RC version I’ve been using is very stable and feature-complete.

Users. Essentials supports up to 25 users, whereas Foundation supports only up to 15 users.

Processor count. Essentials supports servers with up to two physical processors, whereas Foundation supports just one. (Don’t confuse this with cores, however: Both support whatever number of cores your processors contain.)

Hyper-V. Neither products support the Hyper-V role, which was actually a temporary stumbling block for my own installation. (You can virtualize Essentials on Windows Server 2012 Standard or Datacenter, but not Foundation: Remember, it comes with new server hardware only.)

Active Directory. Both products support Active Directory (AD) but approach this functionality in completely different ways. With Essentials, you must create a domain during setup (which you can’t change later). Foundation works like the mainstream Windows Server versions: You get a bare installation during setup and can then promote the server to a DC as you would normally. (AD isn’t the only server service that Essentials installs for you: You also get DNS, File Services, IIS Web Services, and Remote Desktop Services preinstalled and preconfigured, in order to support some Essentials-specific functionality I’ll describe in just a moment.)

Server Core. Neither product supports Server Core. But that makes sense: No small business or home office would need such a thing.

Product focus. Aside from the lack of Hyper-V, Foundation is your basic starter version of Windows Server 2012. That’s both good and bad: It features the same obtuse management tools (the sometimes awful new Server Manager, for example) as the mainstream editions. So it needs experienced IT pros to configure and manage it. Essentials, however, is about as simple as servers get: In addition to pre-configuring a domain for you, Essentials has integrated file and media sharing, centralized PC backup (Windows 7 and Windows 8) and network health monitoring and reporting, remote and web access, simple Group Policy, and optional integration with Office 365 or hosted or on-premises Exchange Server. It’s the spiritual successor to Small Business Server, minus the on-premises Exchange, SharePoint, and SQL, in a nod toward the way today’s small businesses really work.

Management. Essentials includes a third-generation version of Microsoft’s excellent Dashboard management interface, which provides a friendly front end to most server administration needs. If you venture too far into the rabbit hole, you might need to run Server Manager or another traditional management tool, but for the most part you won’t need to. Foundation, as noted above, only includes these more complex management tools. It’s not something typical users could handle.

Upgrading. Both products can be upgraded to Windows Server 2012 Standard, in place, if the environment grows. This is fantastic, of course, but it has interesting ramifications in the case of Essentials, because of that product’s many unique built-in features (such as centralized PC backups). I’ll be reviewing Windows Server 2012 Essentials when the final version ships, and I’ll have more information about these issues at that time.

OK, there’s probably more, but that’s the high-level stuff. How do you choose between them?

Returning to my original point, you should choose Foundation only if you have at least some in-company IT staff and/or are comfortable outsourcing management to a Microsoft partner or solution provider. (And, of course, if that company has 15 or fewer employees.) Essentials makes more sense for those organizations with no IT staff at all, and I don’t see a huge market for partners supporting Essentials.

The other way to look at this is that Essentials is, in my mind, ideal for any modern startup of just a few people. Today’s startups will do email, calendaring, and collaboration in the cloud and won’t want expensive and complex on-premises servers. What Essentials brings to this party is on-site storage (with redundancy if you need it), the centralized PC backup stuff, simple remote access, and more. It’s basically a plug-and-play server appliance.

In my mind, it’s all about Essentials. But you should understand the options so that you can choose the version that makes the most sense for you. (And if you have a valid TechNet or MSDN subscription, you can evaluate both products -- with Essentials in near-final RC form -- right now.)