1B is the Air Force Specialty Code (AFSC) for cyber warfare. The 1B4X1 AFSC is for cyber warfare operations.
The AFSC is used for: Promotions, Assignments, Training opportunities.
The Duty Air Force Specialty Code (DAFSC) is the AFSC of the slot that you are assigned to. The Control Air force Specialty Code (CAFSC) is used for promotions, assignments, and training opportunities.