The police are the official organization that is responsible for making sure that people obey the law.

Police are men and women who are members of the official organization that is responsible for making sure that people obey the law.

If the police or military forces police an area or event, they make sure that law and order is preserved in that area or at that event.

If a person or group in authority polices a law or an area of public life, they make sure that what is done is fair and legal.