As the speed of technological advances accelerated in civilian applications, so too warfare became more industralised. The newly invented machine gun and repeating rifle redefined firepower on the battlefield, and, in part, explains the high casualty rates of the American Civil War. The next breakthrough was the conversion of artillery parks from the muzzle loading guns, to the quicker loading breech loading guns with recoiling barrel that allowed quicker aimed fire and use of a shield. The widespread introduction of low smoke (smokeless) propellant powders since the 1880s also allowed for a great improvement of artillery ranges.
What is the military? In simple terms, the U.S. Armed Forces are made up of the five armed service branches: Air Force, Army, Coast Guard, Marine Corps, and Navy. There are three general categories of military people: active duty (full-time soldiers and sailors), reserve & guard forces (usually work a civilian job, but can be called to full-time military duty), and veterans and retirees (past members of the military). And of course there are the millions of family members and friends of military members, past and present. But you're here to learn more about the military. There is much to learn! So first the basics. Exactly who is in charge?
It is critical to know how ASVAB scores are calculated and what they are used for. The Armed Services Vocational Aptitude Battery (ASVAB) tests are used to identify whether a candidate is qualified to enlist in a particular branch of the U.S. Military. The ASVAB test is also used to determine which military jobs (referred to as MOS for Military Occupational Specialties) a candidate is best suited for. ASVAB scores can also be used by test takers to help explore which careers they may be a good fit for them – whether they go into the military or not. While no one officially passes or fails the ASVAB, each branch of the military has specific minimum scores required for enlistment. Your scores also affect the type of military job, enlistment bonuses and salary you are eligible for.
Limited Duty Officer: due to the highly technical nature of some officer billets, the Marine Corps, Navy and Coast Guard employ a system of promoting proven senior enlisted members to the ranks of commissioned officers. They fill a need that is similar to, but distinct from that filled by warrant officers (to the point where their accession is through the same school). While warrant officers remain technical experts, LDOs take on the role of a generalist, like that of officers commissioned through more traditional sources. LDOs are limited, not by their authority, but by the types of billets they are allowed to fill. However, in recent times they have come to be used more and more like their more-traditional counterparts.
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.