Escort, fleet, and large fleet destroyers

Did each Royal Navy destroyer class have a specific operational role during the Second World War?

Not usually; Hunts were escort destroyers, while the rest broadly divided into fleet and large fleet destroyers with general-purpose duties.

British destroyer classes did not each have an entirely separate operational mission. The Hunt class was a clear escort type optimized for convoy and anti-submarine work. Beyond it, the service broadly distinguished ordinary fleet destroyers from larger fleet destroyers. The categories reflected differences in endurance, armament, and formation employment while preserving a strong general-purpose character.