What is a security clearance?

A security clearance is fundamentally a determination made by an authorized agency regarding an individual's eligibility to access classified information. This process involves a thorough background check, assessing factors such as loyalty, reliability, and trustworthiness of the individual.

In the context of national security, access to classified information is restricted to ensure that only those who have been vetted and approved can view sensitive material. This is particularly crucial within the Department of Defense and other government agencies, where the protection of classified information is essential for national security.

The other choices do not align with the definition of a security clearance. A measure of an employee's skill level relates to performance evaluations rather than access to information. A tiered access level for software pertains to permissions associated with software applications rather than personnel clearance. Lastly, a certification for cybersecurity professionals refers to credentialing within the field and does not imply any direct connection to classified information access.