A default judgment is a legal ruling that occurs when one party to a lawsuit fails to respond or defend their case, resulting in a victory for the other side. In essence, it means that because the defendant did not contest the claims made against them by the plaintiff, the court has determined that they are responsible and owe damages as per the original complaint filed. This type of judgment is typically entered when the defendant fails to respond or appear in court after being properly served with legal papers, or if they fail to defend themselves adequately during a trial. Once a default judgment is issued, it becomes a legally binding order that must be obeyed by the losing party.