Having security clearance is one of the most important qualifications for landing an exclusive job within the government, as it puts people at an advantage over other applicants applying for similar positions.
Security clearance is critical for prospective employees in the Department of Defense (DoD) and other agencies because it grants a person access to classified information (such as state and national security secrets) as well as to areas that are normally restricted.
A number of private positions outside of the government also require a person to have security clearance, making it an even more crucial qualification to have on one's resume.
After taking the appropriate steps to attain security clearance, the person will then undergo a briefing on the "proper safeguarding of classified information and on the criminal, civil, and administrative sanctions that may be imposed on an individual who fails to protect classified information from unauthorized disclosure," according to the National Archives.
Finally, depending on the type of clearance obtained, it will be required to be re-investigated from time to time at least every five years, according to the Department of State's website.