What you'll learn: Cell biology, division and operations; genetics; evolution; plant and animal biology; nutrition; human anatomy and physiology; ecology; matter, atomic structure, the periodic table, and chemical reactions; measurement; nuclear chemistry; motion, force, energy, and work; fluids; waves and sound; and geology, meteorology, oceanography, and astronomy

A military or an armed force is a professional organization formally authorized by a sovereign state to use lethal or deadly force and weapons to support the interests of the state. It typically consists of branches such as an Army, Navy, Air Force, and in certain countries the Marines and Coast Guard. The task of the military is usually defined as defense of the state, and its citizens, and the prosecution of war against another state. The military may also have additional sanctioned and non-sanctioned functions within a society, including, the promotion of a political agenda, protecting corporate economic interests, internal population control, construction, emergency services, social ceremonies, and guarding important areas. The military may also function as a discrete subculture within a larger civil society, through the development of separate infrastructures, which may include housing, schools, utilities, logistics, health and medical, law, food production, finance and banking.

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.
A good score on the ASVAB is different than a minimum required score.  Each of the military branches will have their own minimum required scores (see below).  In practice, however, each branch will be more selective in their recruiting.  A score of 50 on the ASVAB implies that you scored as well or better than 50% of comparable test-takers.  Since ASVAB scores are used for many purposes (e.g., enlistment eligibility, military job placements, and career exploration), it is important that you score well on the ASVAB.  A score of 60 or better should be your minimum target.
Each service has a uniformed head who is considered the highest-ranking officer within their respective service, with the exception of the chairman and vice chairman of the Joint Chiefs of Staff, and the chief of the National Guard Bureau. They are responsible for ensuring personnel readiness, policy, planning and training and equipping their respective military services for the combatant commanders to utilize. They also serve as senior military advisors to the President, the Secretary of Defense, their respective service secretaries, as well as other councils they may be called to serve on. They are as follows:
The Arithmetic Reasoning section of the test measures your ability to solve arithmetic word problems. You may be asked questions such as “If the tire of a car rotates at a constant speed of 552 times in 1 minute, how many times will the tire rotate in half an hour?” Therefore, reviewing common math key words associated with each operation is recommended. For example, if you see the key words “in all,” the problem deals with addition. If the problem asks you to “find the difference,” you are being asked to subtract. If a question asks “how many times” per day or week, you know you are dealing with multiplication. If it asks “how many in each,” you should be thinking about division. The CAT-ASVAB has 16 questions in 39 minutes; the paper-and-pencil version has 30 questions in 36 minutes.

After World War II, with the onset of the Cold War, the constant technological development of new weapons was institutionalised, as participants engaged in a constant 'arms race' in capability development. This constant state of weapons development continues into the present, and remains a constant drain on national resources, which some[who?] blame on the military-industrial complex.

Figure 2.7 shows FY 1977 as the low point and FY 1992 as the high point in accessing recruits in Categories I to IIIA. In FY 1977, 34 percent of accessions scored in the top half of the AFQT distribution. Only 13 percent of Blacks, 19 percent of Hispanics, and 20 percent of "Others" scored in Categories I–IIIA. [3] Fifteen years later, in FY 1992, the majority of minority accessions achieved scores in the I–IIIA range (Blacks - 56 percent, Hispanics - 67 percent, "Others" - 67 percent). Hispanics have shown the most marked increase, with a 48-percentage-point gain in Category I to IIIA accessions from FY 1977 to FY 1992.

The AFQT score is a percentile score. What does that mean? In 1997, a study, known as the "Profile of American Youth," was conducted by the Department of Defense in cooperation with the Department of Labor. DOD administered the ASVAB to around 12,000 individuals, ranging in age from 16 to 23. Your AFQT score is a comparison of how well you scored on the four subtests, compared to those who took the ASVAB as part of the 1997 survey. In other words, if you have an AFQT score of 70, that means you scored as well or better than 70 percent of those 12,000 folks.
Military law introduces offences not recognised by civilian courts, such as absence without leave (AWOL), desertion, political acts, malingering, behaving disrespectfully, and disobedience (see, for example, Offences against military law in the United Kingdom).[23] Penalties range from a summary reprimand to imprisonment for several years following a court martial.[23] Certain fundamental rights are also restricted or suspended, including the freedom of association (e.g. union organizing) and freedom of speech (speaking to the media).[23] Military personnel in some countries have a right of conscientious objection if they believe an order is immoral or unlawful, or cannot in good conscience carry it out.
Sergeant Leigh Ann Hester became the first woman to receive the Silver Star, the third-highest U.S. decoration for valor, for direct participation in combat. In Afghanistan, Monica Lin Brown was presented the Silver Star for shielding wounded soldiers with her body.[45] In March 2012, the U.S. military had two women, Ann E. Dunwoody and Janet C. Wolfenbarger, with the rank of four-star general.[46][47] In 2016, Air Force General Lori Robinson became the first female officer to command a major Unified Combatant Command (USNORTHCOM) in the history of the United States Armed Forces.[48]