What is the difference between a plaintiff and defendant in a civil case? The defendant is the person or organization accusing another of wrongdoing while the plaintiff is the person or organization being accused of wrongdoing. The defendant is the person or organization that must pay court fines while the plaintiff is the person or organization that must pay a penalty for wrongdoing. The defendant is the person or organization being accused of wrongdoing while the plaintiff is the person or organization accusing another of wrongdoing. The defendant is the person or organization that must pay a penalty for wrongdoing while the plaintiff is the person or organization that must pay court fines.