In complete honesty, one can say that the test identifies with an entire life's worth of knowledge. It essentially pulls from 3 different aspects. First, it draws from concrete facts that were acquired from all areas of a person's educational career. Secondly, it draws from a person’s ability to comprehend and use context clues to make assumptions. Lastly, it draws from a person’s physical/verbal skills to see if they can properly administer those more physical aspects. Overall this is why people have identified it as the “SAT on steroids.”
One set of ASVAB scores – Career Exploration Scores – tells you your current strengths in verbal, math, science, and technical skills.  The scores allow you to compare your test performance with that of other students at your grade level and can help you determine your readiness for further education and training in different career areas.  You will also receive a Military Entrance Score that is important for entry into the Armed Services.  You can discuss your score with a military recruiter.
The ASVAB also known as the Armed Services Vocational Aptitude Battery is a test that measures your aptitude which is how well you do something.  A common mistake by most people is thinking that it is a measure of you IQ. Many people either forget this or don’t know this and they get worked up about the exam.  Saying that, it is also important to take a ASVAB sample test to insure you know what type of questions will be asked.    Another thing to keep in mind is every person in the armed forces has to take the exam and you are not being called out to take it. 

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,[8] 10% in the UK,[9] 13% in Sweden,[10] 16% in the US,[11] and 27% in South Africa[12]). 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.[13]
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.

Again, would you rather go into the ASVAB unsure of what to expect and not knowing if you studied the right things or would you prefer to have taken similar tests covering content commonly tested for on the real thing? Taking practice tests is a great way to build your knowledge, your confidence and your ASVAB familiarity so that you feel relaxed and confident on test day.

You are tested in four critical areas — Arithmetic Reasoning, Word Knowledge, Paragraph Comprehension and Mathematics Knowledge (see below) — these scores count towards your Armed Forces Qualifying Test (AFQT) score. The AFQT score determines whether you’re qualified to enlist in the U.S. military. Your scores in the other areas of the ASVAB determine how qualified you are for certain military specialties. Score high, and your chances of getting the specialty/job you want increase. The better score you get, the better chance you have of pursuing the specialty or field that you desire.
If you’re planning on using your scores for military enlistment, you may be hoping to achieve a score that is high enough for a specific signing bonus. While it’s natural to want to do your best, putting extra pressure on yourself can cause unnecessary anxiety. Take a few deep breaths, relax, and remember that taking the test is only part of the entire recruitment process.
Under current Department of Defense regulation, the various components of the U.S. Armed Forces have a set order of seniority. Examples of the use of this system include the display of service flags, placement of Soldiers, Marines, Sailors, Airmen and Coast Guardsmen in formation, etc. When the Coast Guard shall operate as part of the Department of the Navy, United States Coast Guard Academy cadets, the United States Coast Guard and the Coast Guard Reserve shall take precedence after United States Naval Academy midshipmen; the United States Navy; and Navy Reserve, respectively.[51]
Every single individual that goes through the enlistment process should excel both mentally and physically. That is the number one principle that has consistently inspired this nation to serve these brave and honorable individuals with unwavering efforts. Those efforts officially came to the forefront when the country as a whole decided to correct perhaps the most significant enlistment related problem (passing the Armed Services Vocational Aptitude Battery test). Countless hours of hard work and dedication are currently reflected by the top-of-the-line ASVAB practice tests that this nation offers.