The term 'ARMY DO' is a job description for three different positions. The first position is 'LEE', which stands for Light Equipment Engineer, and is responsible for maintaining and repairing military vehicles. The second position is 'YOU', which stands for Youth Officer, and is responsible for providing guidance and support to young people in the armed forces. The third position is 'CREWCUT', which stands for Crew Chief, and is responsible for leading a team of personnel in the field. All three positions are important roles in the military and require specialized skills and knowledge.