What is the origin of the idiom "call it quits" and when to use it?

The idiom "call it quits" has its origins in informal English and dates back to the early 19th century. It is believed to have originated in the United States. The word "quits" in this context means "even" or "equal." When two parties in a game or competition decided to end it and declare themselves even, they would "call it quits." The idiom "call it quits" is used to indicate that a particular activity, situation, or relationship is being ended, usually because the participants feel that they are on equal terms, or they want to bring it to a close without further dispute or continuation.