If you've applied for Social Security benefits and were denied, you must appeal the denial within 60 days.  If you've appealed the first denial by requesting a "reconsideration", and received another denial letter, then your next step is to request a hearing with an administrative law judge.

The hearing will be presided over by a a Federal Administrative Law Judge.  There will also be other experts at the hearing, who try to help the judge find out whether you're disabled, and whether you're able to do certain jobs.  You will be asked a series of questions by the judge and by these other experts concerning your disability and your ability to perhaps find other kinds of jobs to earn a living.