There's only one real difference between entrepreneurs and daydreamers, and that is profit.  Entrepreneurs are the quintessential daydreamers.  They are idea people, always brainstorming new and innovative business concepts.  However, entrepreneurs also are people of action, of dynamism, who are almost never inert, are always trying something, and not just thinking about it.
You cannot get paid for daydreaming — though if you could, it would be an entrepreneur who made it work.  Any idea, no matter how great, will stay an idea unless you can find a way to monetize it and transform it into a business plan.