The difference between detention center and prison: detention center is used to hold suspects suspected of criminal offences. Please note that they are suspicious. This is because the public security organs did not investigate the case clearly and were afraid that the suspects would escape, so they were put into the detention center first to prevent the suspects from escaping, hiding and committing suicide. If the suspect is found guilty, the identity of the suspect will be turned into a prisoner and held in prison according to law. Those sentenced to fixed-term imprisonment or criminal detention control shall be placed in a detention center on the spot. In prison, the suspect was found guilty and the court pronounced the corresponding punishment according to law. The suspect became a prisoner and was held in prison to serve his sentence according to law.
References:
Baidu Encyclopedia-Regulations on the Administration of People's Republic of China (PRC) Detention Center