A more thorough explanation:

A confidential source is someone who gives information to either law enforcement or a journalist with the promise that their identity will be kept secret. This means that the person who provides the information will not be identified publicly or in court.

For example, a person who witnesses a crime may be afraid to come forward because they fear retaliation. They may choose to speak to the police as a confidential source, providing information that can help solve the crime without putting themselves in danger.

Another example is a journalist who receives information from a confidential source about a story they are working on. The journalist may promise not to reveal the source's identity in order to protect them from any negative consequences that may result from the information being made public.

Both law enforcement and journalists have a responsibility to protect the identity of their confidential sources. This protection is guaranteed by the Federal Freedom of Information Act for law enforcement and the First Amendment for journalists.