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. 
After a candidate has completed the ASVAB they must wait one calendar month before retaking the exam. An additional calendar month must pass before retesting a second time. Six calendar months must pass before retaking the test a third time. The scores received from the ASVAB may be used for enlistment for up to two years from the initial test date. 

ASVAB CEP test results are sent to students’ schools so they can explore career options with counselors. The scores show how well the student did on each subject, and how they compare with others who took the test. There are three composite scores in Verbal, Math, and Science and Technical skills, and the Armed Forces Qualification Test (AFQT) score is also reported.

Tests are administered at participating schools. Neither schools nor students incur any costs for taking the ASVAB or using the Career Exploration Program. A test administrator is provided for every testing session and that person has no additional recruitment responsibilities. Various accommodations are available for the ASVAB, such as having questions read aloud, providing extra time, and other accommodations. School staff members are responsible, however, for tests that are administered with accommodations because test administrators are only able to administer the ASVAB by following the standardized procedure. If the test is being used for enlisting, only scores obtained during standardized test sessions (with no accommodations) can be used.
The Mechanical Comprehension section of the ASVAB practice test measures your understanding of basic mechanical principles and mechanisms. You may be asked why an intake valve on a pump opens when the piston goes down, or what direction friction is going when shown a diagram of a skier. The CAT-ASVAB has 16 questions in 20 minutes; the paper-and-pencil version has 25 questions in 19 minutes.
This continued in the 19th century, with publications like Punch in the British Empire and Le Père Duchesne in France, poking fun at the military establishment. This extended to media other print also. An enduring example is the Major-General's Song from the Gilbert and Sullivan light opera, The Pirates of Penzance, where a senior army officer is satirised for his enormous fund of irrelevant knowledge.
The ASVAB tests recruits in ten different areas. It is presented as ten short tests administered over a three-hour period. Traditionally, the ASVAB is a “proctored” test, meaning that it has required supervision to administer in order to maintain the integrity of the test. However, changes to military recruiting and technology in general have helped the ASVAB evolve as a 21st century tool.
In order to take the ASVAB at a MEPS for enlistment purposes, an individual will need to speak with a recruiter and schedule a time to take the test. ASVAB testing at a MEPS is self-paced and taken on a computer, and it may be retaken after a one-month waiting period.  Entitled the CAT-ASVAB, the test is adaptive – meaning it adapts to your ability level.
The AFQT score is a percentile ranking between 1 and 99 that shows where your score is placed in relation to others. For example, if you score a 54 on the AFQT, this means that you scored as well as or better than 54% of other recruits. If you are not satisfied with your score and wish to retake the test to improve your chances at getting selected, you must wait a month before taking it again. You can retake the test as many times as you want, but after 3 attempts the waiting period jumps to 6 months.
The Armed Forces Qualification Test (AFQT) derives from the more comprehensive, 10-subtest Armed Services Vocational Aptitude Battery (ASVAB). Scores on the four ASVAB math and verbal subtests are used to calculate an AFQT score, which determines whether an individual is generally qualified to enlist. Performance on all 10 ASVAB subtests, meanwhile, ascertains an enlistee's qualifications for specialized work within the military and possible incentives for enlistment.
The Armed Services Vocational Aptitude Battery is more commonly known as the ASVAB Test. If you are interested in a military career, you will need to pass this challenging test in order to qualify. It is used for all branches of the military which includes the Army, Navy, Air Force, Marines, National Guard, and Coast Guard. It is also used to gauge your abilities in specific areas that may be relevant to your job assignments within the military. For more information about the exact details of this exam, check out our article titled What is the ASVAB Test?
The projected active duty end strength in the armed forces for fiscal year 2017 was 1,281,900 servicemembers,[6] with an additional 801,200 people in the seven reserve components.[6] It is an all-volunteer military, but conscription through the Selective Service System can be enacted at the President's request and Congress' approval. All males ages 18 through 25 who are living in the United States are required to register with the Selective Service for a potential future draft.

The test must be completed if you wish to serve in the Army, Navy, Marines, Air Force, or Coast Guard. The test can also be taken as a career-exploration tool if you are a high school sophomore, junior, or senior. It takes approximately three hours to complete. If you take the computerized version of the test, results are given immediately. If you complete a paper and pencil test, you’ll get results within two weeks.

The various armed forces adopted all of those aspects in 1976. At that point in time, the test was in its written form rather than today’s more common form (computerized test format). The written form covers all of the previously mentioned areas as well, which is why both forms are still available. All-in-all that answers the question concerning the intention of the test.