The simplest definition is also the worst. We often see enterprise as a way of defining a company as large -- over 1,000, over 10,000. Take your pick. We see it attached to Internet prominence. Enterprise is a word that comes to mind alongside Wal-Mart and Amazon.
It provides a context for the dizzying scope of business application software behemoths like SAP and Oracle. It also has various other incorrectly applied, pseudo definitions of convenience: geographically distributed business, e-business, or, perhaps, "User-of-Expensive-ERP-Software". These definitions aren't actually wrong, but they are certainly incomplete.
What It's Not
It is not about size; just about any business, of any size, can become an "enterprise." And it is not about software per se; the implementation of a premium ERP system isn't what makes your company an enterprise, and not implementing a premium ERP system doesn't keep you from becoming one.
Because of the Internet, and thanks to modern database technology and object-oriented application resources, any company with determination, creativity, and willingness to let their business processes evolve radically can march onto the playing field. The Internet has merely leveled it.
Enterprise isn't about size and it isn't about the Web. We get the most out of the word when we think of it as a frame-of-mind.
What is enterprise, then? Here are some possibilities:
There are more things we could add to this list, and there would be some partial truth in each. But none captures the true core of enterprise, the one indispensable feature that sets a company apart, both internally and externally, making it a viable 21st century player in business.