In the legal context, a complaint is a formal document that initiates a lawsuit.
It sets out the facts and legal grounds for the claim and states the relief that the plaintiff (the person or party bringing the lawsuit) is seeking.
A complaint is usually filed in a court of law and is directed at a specific defendant (the person or party being sued). It outlines the wrongdoing that the defendant is alleged to have committed and explains why the plaintiff is entitled to relief. The complaint serves as the basis for the lawsuit and sets the stage for further legal proceedings.