The Ministry of Defense is a government department responsible for managing a country's military forces and ensuring national security. It oversees the armed services, including the army, navy, and air force, and is involved in defense policy, military operations, and resource allocation. In many countries, the Ministry of Defense works closely with other government agencies and international organizations to address security challenges. It also plays a role in defense research and development, procurement of military equipment, and training of personnel to maintain a capable and ready military force.