Military education and training is a process to establish and improve the capabilities of soldiers in their respective duties. Military education can be a compulsory or voluntary duty. Before any person can operate technical equipment or be on the battle field, he or she has to take a medical and a physical test. If they pass, they may begin the primary training, recruit training. Recruit training attempts to teach the basic information and training in techniques necessary to be an effective soldier. To achieve this, recruits are drilled mentally, technically, and physically. The drill instructor has the task of making the recruits fit for military use. After recruit training, many service members undergo advanced training more in line with their chosen or assigned duties. This range from navy training to studies of explosives, and military technology and equipment is often taught. Many large countries have several military academies, one for each branch of the service, that offer college degrees in a variety of subjects, similar to other colleges. However, academy graduates usually rank as officers, and as such have many options besides civilian work in their major subject. Higher ranking officers also have further educational opportunities.