Passing one's driver's permit test or driver's test and earning a driver's license is a rite of passage. While it does not confer upon the person who receives it the full rights and responsibilities of adulthood, and it certainly does not allow him or her to buy alcohol before the age of 21
Obtaining a driver's license has many prerequisites; this certification is not automatically awarded at a certain age, as one's competency to operate a motor vehicle must be verified. Most times, before one earns a driver's license he or she will apply for a driver's permit. This usually involves at least the passing of a written driver's permit test.
As for the driver's test to get a full license, this will almost certainly involve both a written test on driving theory as well as a performance test on a road course with a licensed reviewer. In some states, such as Ohio, the driver's test will also involve a maneuverability test that has the applicant drive through a series of cones both with the car in drive and in reverse as an added assessment of driving prowess. In case of a failure of an individual part of the driver's test, the child applicant will be able to retake that failed section again after a certain amount of time has elapsed.
As noted, the age by which juveniles may first sign up for a driver's permit test varies from place to place. In North and South Dakota, for example, one as young as 14 can earn a learner's permit, while in New Jersey, a teen must wait until 17 to become the owner of a provisional license. As for a driver's license, usually the wait is longer, with the range in ages for those who may get a license spanning 16 to 18 for most states.
There are states, meanwhile, notably New Hampshire, that do not have a learner's permit program, and others that automatically confer the rights of a license to those who pass the needed tests. For those states who fall into neither of those categories, a graduated driver's license system is a popular option, in which the young driver moves between a permit, a provisional license, and a full license. The privileges for each stage varies the higher up you go.