What's the difference between an anesthesiologist and a crna?

Training: An anesthesiologist is a physician who has completed medical school plus four years of residency training. A crna (certified registered nurse anesthetist) is a registered nurse who has completed nursing school plus a 2-3 year graduate degree in anesthesia. Depending on local practice, anesthesiologists and crnas may work collaboratively or independently.

Med school: Anesthesiologist go through medical school and then do at least four more years of training to finish an internship and residency. Nurse anesthetists go through nursing school and then they may apply for a two and a half year training program after working some time as a nurse.

Training: CRNA is an advanced nurse practioner Anesthesiologists are MD physicians