Lieutenants are military officers who typically rank just below captains. They play a crucial role in leading and managing troops, often serving as the primary point of communication between higher-ranking officers and enlisted personnel. Their responsibilities can include planning missions, training soldiers, and ensuring that orders are executed effectively. In many organizations, such as the United States Army or Navy, lieutenants may specialize in various fields, including infantry, logistics, or engineering. They often hold a commission, which means they have been officially appointed to their position, and they usually have completed a military academy or officer training program.