It's nice to be somewhat disturbingly anoracky at times isn't it? Anyway, to add my own sub splitting of hairs to this, Windows 3.1 and 95 weren't 'home' versions of Windows.
The concept that there was a very of Windows for the home and a version for business didn't exist until Windows 98 came out.
Windows NT (which started at version 3.1) was designed not necessarily for businesses, but for power users who needed something more robust, or who wanted to run Windows on non-Intel platforms (the original release would run on the PowerPC platform - the most prominent implementation of which came from Apple, so yes somewhat oddly there is actually a version of Windows which will natively run on a Mac!).
Many (most actually) businesses and institutions ran Windows 3.1, many ran Windows 95. Indeed most businesses who migrated to Windows 2000 did so from Windows 95 rather than from NT.
Arguably, not until Windows 2000 which added support for modern hardware and technologies lacking in NT, did the strict 'home/business' duality come into being; if you were a business developing DirectX applications, you had to run Windows 98 before Windows 2000, because NT wouldn't support it properly. Ditto for USB hardware.
And I believe, only Windows ME/2000 were ever specifically plugged as home and business versions (with ME being the 'Home version of the world's favourite software' and 2000 being the 'reliable operating system for business').
Windows XP did merge the two product lines. Or rather, the old DOS-based line was discontinued, and XP Home was released as a cut down version of Professional (all but the final release candidates of Longhorn came only in what is now the 'professional' version; there were no standalone 'home' builds during most of the testing). They are in essence the same thing. Microsoft could ditch that distinction and just market a one size fits all version of Windows as they have done in the past, but why do that when they can make more money with the way they've done it (especially with the server lines)?
The current situation is as close to a single Windows as we'll ever get.
Version 4.00.950x (where x is either A, B, or C) is Windows 95. Flavour B introduces FAT32, flavour C introduces USB but wasn't very good at it IIRC. Lack of a letter after the version implies the original release.
There were 4 builds and 5 variants of Windows 95. The original version was identical in both OEM and retail flavours (except for the setup programme which threw a paddy if you tried to upgrade with an OEM version, but the security was very weak - just renamed WIN.COM to something else and it'll work fine). It notably did NOT include Internet Explorer in any way, shape or form.
The same build was later packaged with IE1 (which curiously identifies itself as version 4 in the about box). Whilst the OEM version was upgraded further, the retail version stayed like this for the life of Windows 95.
Shortly after, an 'A' version (OEM only, as are all subsequent versions) was released. This was a new build with a new version number, but the only difference I can find is that it comes with IE2 instead of IE1 (and does anyone actually know what the difference between IE1 and 2 is? I've yet to find a single difference).
Not so longer after that, there came a 'B' release (what's commonly known as the 'OSR2' version). This added USB support and upgraded IE again to version 3.02. Curiously, the USB support was supplied in the form of a patch which you had to manually install after installation, and IE3.02 was supplied as an upgrade on the installation CD; the native install gave you IE3.0.
Finally, a quite rare 'C' release came out a few months before Windows 98. This was like an embryonic Windows 98; it basically was just the same old Windows 95 OSR2 but with IE4 and the 'desktop upgrade' installed. Although again it was a separate build, I don't think there is any additional functionality in it that can't be gained by installing IE4 on Windows 95 OSR2.
