E-4 is a military rank used in various branches of the armed forces, including the U.S. Army, U.S. Air Force, and U.S. Navy. In the Army, E-4 is known as Corporal or Specialist, while in the Air Force, it is referred to as Senior Airman. This rank typically indicates a soldier or airman who has gained some experience and responsibility, often serving as a team leader or in a specialized role. In the U.S. Navy, the E-4 rank is known as Petty Officer Third Class. Individuals at this level have usually completed basic training and advanced training in their specific field. E-4 personnel are expected to demonstrate leadership skills and contribute to their unit's mission while continuing to develop their professional abilities.