Where modern frigates, destroyers, and cruisers diverge

In the VLS era, where does the distinction between frigates, destroyers, and cruisers lie?

The operating navy defines it; broadly, ASW escorts tend to be frigates and air-warfare escorts destroyers, while many perform cruiser-like duties regardless of label.

Modern frigate, destroyer, and cruiser labels depend on the operating navy's conventions. Many escorts perform the cruising duties that a naval officer in the 1920s would have associated with cruisers. A useful working distinction is that anti-submarine escorts are often called frigates and air-warfare escorts destroyers, although national politics can override it. Displacement is equally unreliable: China's Type 055 is larger than some ships still formally called cruisers, including the Slava class. Expected duties and the hull needed to perform them explain more than the label alone.