The obligations of military employment are many. Full-time military employment normally requires a minimum period of service of several years; between two and six years is typical of armed forces in Australia, the UK and the US, for example, depending on role, branch, and rank. Some armed forces allow a short discharge window, normally during training, when recruits may leave the armed force as of right. Alternatively, part-time military employment, known as reserve service, allows a recruit to maintain a civilian job while training under military discipline at weekends; he or she may be called out to deploy on operations to supplement the full-time personnel complement. After leaving the armed forces, recruits may remain liable for compulsory return to full-time military employment in order to train or deploy on operations.
Each year, many high school and postsecondary students take the free Armed Services Vocational Aptitude battery (ASVAB). The ASVAB is the most widely used multiple-aptitude test battery in the world. It consists of eight tests that measure your skills and abilities in the following areas: General Science; Arithmetic Reasoning; World Knowledge; Paragraph Comprehension; Mathematics Knowledge; Electronics Information; Auto and Shop Information; Mechanical Comprehension.