Probationary period
If you're a new employee or supervisor in the Federal Government, you may have to complete a one-year probationary period. Some agencies may require a longer probationary period and other agencies may not require it at all.
During the "probationary period" your employer will decide if you're the right person for the job. If you're not the right person for the job, the employer can fire you at any point during the probationary period.