What is the difference between the recruitment published by the hospital itself and the recruitment published by the Health Bureau?

As far as I know, the open recruitment of health bureau is compiled, but hospitals are possible. It can be compiled, contracted and sent. I am a fresh student this year, and I am going to take the open recruitment examination of the Health Bureau. It is compiled. If I pass the exam, I will become a staff member of the Health Bureau. I took part in the hospital recruitment first, but the hospital asked me to take the examination of the health bureau. If I pass the exam, I can go directly to their hospital. I am a nurse. Hehe, isn't it a little wordy?