This is a very intriguing question. Intriguing in the sense that most small business owners would call themselves entrepreneurs, but not all entrepreneurs would call themselves small business owners. Not even if their revenue is small enough to qualify as a small business in the traditional sense.
Seth Godin touches on this topic on his blog in a post titled So, what’s wrong with small business? Godin states
The distinction I’ve always made is that an entrepreneur is trying to make money while she sleeps, and does it with someone else’s money! That she builds a business bigger than herself, that scales for a long time, that is about processes and markets. A small businessperson, on the other hand, is largely a freelancer with support, someone who understands the natural size of her business and wants to enjoy the craft of doing it every day.
I think it’s critical that you know what type of business you are building. As this will drive many of the trade-offs you must make in your business model.