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?
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. 

The United States Armed Forces[8] are the military forces of the United States of America. It consists of the Army, Marine Corps, Navy, Air Force, and Coast Guard.[9] The President of the United States is the Commander-in-Chief of the U.S. Armed Forces and forms military policy with the U.S. Department of Defense (DoD) and U.S. Department of Homeland Security (DHS), both federal executive departments, acting as the principal organs by which military policy is carried out. All five armed services are among the seven uniformed services of the United States.[10]
The Word Knowledge section of the test gauges your ability to recognize the meaning of words both individually and when used in a sentence. A question may be phrased as, “‘Antagonize’ most nearly means: embarrass, struggle, provoke, or worship.” Because there are so many words in the English language, you may find it difficult to study the specific words on the test. However, striving to improve your language and vocabulary usage with a practice test like this one can help you not only in preparing for the ASVAB test but also in your career and personal life. The CAT-ASVAB test has 16 questions in 8 minutes, while the paper-and-pencil version has 35 questions in 11 minutes.
Mathematics Knowledge tests the ability to solve problems by applying knowledge of mathematical concepts and applications. The problems focus on concepts and algorithms, and involve number theory, numeration, algebraic operations and equations, geometry, measurement and probability. Mathematics Knowledge is one factor that characterizes mathematics comprehension; it also assesses logical thinking.