The four most important sections of the test—Word Knowledge, Paragraph Comprehension, Arithmetic Reasoning, and Mathematics Knowledge-make up your Armed Forces Qualifications Test (AFQT) score. Your AFQT score ranges from 0 to 100 and determines if you are able to enlist in the military and which jobs and programs you may qualify for when you are in.
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.