How do you define "professional" photographer?

Defining a "professional" photographer often sparks debate within the creative community. While traditional views equate professionalism with earning income from photography, the essence of being a professional extends beyond financial compensation. It encompasses a commitment to quality, mastery of technique, and a deep understanding of elements like composition and lighting. Many passionate photographers, even without paid work, exhibit a level of skill that rivals or surpasses those who are commercially established. How do you perceive the distinction between professional, amateur, and hobbyist photographers?