I admit to more than just a small degree of aloofness toward business and commerce, but apparently even those who don't keep their distance aren't exactly sure just what "enterprise" means. The Wikipedia entry for Enterprise Software suggests that the definition is quite a bit fuzzier than most businesspeople might want to admit:
The word enterprise can have various connotations. Sometimes the term is used merely as a synonym for organization, whether it be very large (e.g., a corporation with thousands of employees), very small (a sole proprietorship), or an intermediate size. Often the term is used only to refer to very large organizations. Often the term is used to mean virtually anything, by virtue of its having become the latest corporate-speak buzzword.But it's my guess that it's simpler than that. Enterprise can rather readily be defined as the category of internet users - usually companies, and not particularly small ones at that - that's willing to pay for services that many of us only want to get for free. This willingness, however, isn't simply a blind attachment to the not necessarily verifiable idea that when you pay for something you're getting quality, but instead comes along with the demand that the service being purchased will be robust, secure and sustainable.