Guided-missile destroyer or frigate distinction

What defines guided-missile destroyers and guided-missile frigates?

The labels depend on role and navy, with destroyers usually linked to area air defense and frigates more often linked to point defense or ASW roles.

Displacement alone does not settle the destroyer-versus-frigate distinction, especially across different periods and navies. Task-force role, command seniority, and the common modern split between area-defense destroyers and point-defense or ASW frigates matter as well.