A certified flight instructor (CFI/CFII) certificate allows a commercial pilot to be an educator in aviation. A CFI and/or CFII certificate certifies you to teach other pilot certificate applicants, as well as conduct flight reviews, assess aircraft proficiency, and perform insurance checkouts.
Becoming an instructor will significantly expand your flight knowledge and proficiency, exceeding your expectations of what is typical as a pilot. Being a CFI provides the opportunity to log valuable flight time, gain experience, refine proficiency, and increase safety awareness, all while being paid to fly.