Q. What is standing?
The CourtHelp Glossary defines standing: The right to take part in a case because you have a legal claim or want to enforce a duty or right.
A noted legal textbook gives this lively description:
It is the law's policy to allow only an aggrieved person to bring a lawsuit. One not affected by anything a would-be defendant has done or threatens to do ordinarily has no business suing, and a suit of that kind can be dismissed at the threshold for want of jurisdiction without reaching the merits. When one without the requisite grievance does bring suit, and it's dismissed, the plaintiff is described as lacking “standing to sue” and the dismissal as one for lack of subject matter jurisdiction. A want of “standing to sue,” in other words, is just another way of saying that this particular plaintiff is not involved in a genuine controversy, and a simple syllogism takes us from there to a “jurisdictional” dismissal: (1) the courts have jurisdiction only over controversies; (2) a plaintiff found to lack “standing” is not involved in a controversy; and (3) the courts therefore have no jurisdiction of the case when such a plaintiff purports to bring it.
§ 136. Standing to Sue, Siegel, N.Y. Prac. § 136 (6th ed.)