Is there a difference between a policeman and a criminal policeman?

The police station is a grass-roots organization sent by the public security system; Interpol is a kind of police in the public security system; The task of the police station is to prevent and control all kinds of accidents, manage social security, and maintain public order and household administration; The task of criminal police is to crack down on criminal crimes and undertake major cases such as drug control, anti-gang, anti-terrorism and economic investigation.