Like any employer, the Air Force Civilian Service (AFCS) expects you to be “qualified” when you apply for a position, but unlike some employers, you must also be “eligible” for AFCS positions. What’s the difference? It’s actually simpler than it may sound.
“Qualification” is based on education and/or experience. As with any other employer, you will need to have certain educational and/or work experience in order to be qualified for a given position. For example, if you want a job as a doctor, you need to have gone to medical school. The kinds of background needed are always very clearly detailed in the Job Opportunity Announcement, so be sure you meet those expectations before you decide to apply.
However, even if you are completely “qualified” for a job, you may not actually be “eligible.” In the Federal jobs environment, “eligibility” refers to Federal regulatory requirements that determine who can apply for specific jobs.