A squadron is an administrative and operational formation, conventionally numbering four to nine ships of the same primary-combatant classification. Historically the label applied chiefly to cruisers and larger warships. Destroyers, and later some frigates, entered squadron organization as fleets and ship roles changed. The organizational idea remained stable while the eligible combatants changed.
Chapter · 3:08-3:45
Squadrons organize a navy's primary combatants
A squadron conventionally contains four to nine ships of the same primary-combatant classification, though the eligible ship types changed over time.