Osteopathic medicine (also known as osteopathy) is a complete system of medical care with a philosophy that combines the needs of the patient with current practice of medicine, surgery and obstetrics. It emphasizes the interrelationship between structure and function, and has an appreciation of the body’s ability to heal itself. Doctors of Osteopathic Medicine, or D.O.s, learn to apply the philosophy of treating the whole person to the diagnosis and treatment of illness using conventional medical practice such as medications and surgery, along with osteopathic manipulative techniques (OMM).

Doctors of Osteopathic Medicine (D.O.s) educated in the United States are fully licensed physicians, just like allopathic doctors (M.D.’s).  They practice the full scope of medicine and have the same prescribing privileges.
(thanks to Wikipedia – for help with the wording)