A more thorough explanation:

Definition: Voluntary appearance refers to a party or lawyer's decision to come to court on their own, without being served with a legal summons. This can include participating in a lawsuit by filing an answer, demurrer, or motion, or taking post-judgment steps in the lawsuit in either the trial court or an appellate court.

Example: John is being sued by his former business partner. Instead of waiting to be served with a legal summons, John decides to go to court on his own and file an answer to the lawsuit. This is an example of a voluntary appearance.

Explanation: In this example, John is taking the initiative to participate in the lawsuit without being legally required to do so. By filing an answer, he is submitting himself to the court's jurisdiction and agreeing to be a party to the lawsuit.