A more thorough explanation:

Chambers are private rooms where judges can hear legal matters, talk to lawyers, or conduct business. This term is usually used in the plural form. If a trial is "in chambers," it means that the trial is happening in a courtroom without the public, reporters, or anyone else who is not directly involved in the case.

Chambers can also refer to a hall where a group of people, such as a legislative or judicial body, meet to discuss and make decisions. Additionally, it can be the reception room of someone who holds a high rank or authority.

For example, a judge may hold a meeting with lawyers in their chambers to discuss a case privately. Or, a legislative body may meet in chambers to discuss and vote on a new law. A king or queen may receive important guests in their chambers.