Social Security Disability is based on the inability to work.
The Administrative Law Judge must decide whether you can perform your former jobs, over the last 15 years. And if you cannot, whether you can perform any job. If you are 50 years of age or older, this requirement changes somewhat.
Social Security does not have to provide you a job, or show that there are real job openings in your area. Instead they will ask a Vocational Expert at your hearing, what kind of jobs are available for persons with certain limitations (such as lifting, standing or walking), and how many jobs exist in the area.Usually, if the Vocational Expert finds a job within your limitations then you are not disabled. The question is whether you can prove you have limitations that eliminate the jobs the expert finds for you. If you can do this, then you are disabled.