Private First Class is a military rank used in the United States Armed Forces. The rank is used to signify a junior enlisted rank above Private Second Class and below Corporal. There are several synonyms that may be used to refer to someone holding this rank such as Lance Corporal, Specialist, and Senior Aircraftman. These ranks are used in different branches of the military, but all signify the same level of experience and rank. Other common synonyms for Private First Class include Private, Private Second Class, and Airman Basic. Regardless of the terminology used, these individuals are considered the backbone of the military and are often relied upon to complete critical missions.