As an adjective, military originally referred only to soldiers and soldiering, but it soon broadened to apply to land forces in general, and anything to do with their profession. The names of both the Royal Military Academy (1741) and United States Military Academy (1802) reflect this. However, at about the time of the Napoleonic Wars, 'military' began to be used in reference to armed forces as a whole, and in the 21st century expressions like 'military service', 'military intelligence', and 'military history' encompass naval and air force aspects. As such, it now connotes any activity performed by armed force personnel.
Personnel may be recruited or conscripted, depending on the system chosen by the state. Most military personnel are males; the minority proportion of female personnel varyies internationally (approximately 3% in India, 10% in the UK, 13% in Sweden, 16% in the US, and 27% in South Africa). While two-thirds of states now recruit or conscript only adults, as of 2017 50 states still relied partly on children under the age of 18 (usually aged 16 or 17) to staff their armed forces.
The United States has the world's largest military budget. In the fiscal year 2016, $580.3 billion in funding were enacted for the DoD and for "Overseas Contingency Operations" in the War on Terrorism. Outside of direct DoD spending, the United States spends another $218 to $262 billion each year on other defense-related programs, such as Veterans Affairs, Homeland Security, nuclear weapons maintenance and DoD.
These relationships are seen from the perspective of political-military relations, the military-industrial complex mentioned above, and the socio-military relationship. The last can be divided between those segments of society that offer support for the military, those who voice opposition to the military, the voluntary and involuntary civilians in the military forces, the populations of civilians in a combat zone, and of course the military's self-perception.
Your ASVAB scores determine what jobs you will qualify for in the military. But before you embarrass yourself in front of active duty service members, know that a job in the Army and the Marine Corps is called an MOS, which is an acronym for Military Occupational Specialty. In the Air Force, jobs are called AFSC – Air Force Specialty Code. In the Navy they are known as an NEC - Navy Enlisted Classification and the Coast Guard, jobs are called ratings, or rate for short.