 In modern navies, frigates are used to protect other warships and merchant-marine ships, especially as anti-submarine warfare (ASW) combatants for amphibious expeditionary forces, underway replenishment groups, and merchant convoys.Ship classes dubbed "frigates" have also more closely resembled corvettes, destroyers, cruisers and even battleships.Some European navies such as the Dutch, French, German or Spanish ones use the term "frigate" for both their destroyers and frigates.