A more thorough explanation:

Definition: A preliminary objection is a legal objection raised at the beginning of a case that, if accepted, would make it unnecessary to proceed with the case. In international law, a preliminary objection can be raised to challenge the jurisdiction of a court or tribunal.

Example: If a defendant in an international court case argues that the court does not have the authority to hear the case, this would be a preliminary objection. If the court agrees with the objection, the case would be dismissed without further proceedings.

Another example: In a domestic court case, a preliminary objection could be raised if the plaintiff failed to properly serve the defendant with the legal documents required to start the case. If the court agrees with the objection, the case would be dismissed without further proceedings.

These examples illustrate how a preliminary objection can be used to challenge the validity of a case before it proceeds to trial. By raising a preliminary objection, a party can potentially avoid the time and expense of a full trial if the objection is successful.