Most everyone is familiar with the word "entrepreneurship," but there is another closely-related word that you may not be too familiar with. It is called intrapreneurship.
Intrapreneurship, like entrepreneurship, involves creativity, vision, and business acumen. But the two split off from there. In intrapreneurship, the principles of entrepreneurship are applied to an already-existing business or organization. In other words, the intrapreneur does not own a business. Rather, s/he is an employee working within the framework of an established company, yet essentially applying those same principles of entrepreneurship in order to help keep the company fresh, relevant, and competitive.
For more information, here is another great blog post on the topic of intrapreneurship.