The AIs build Attack Ships and Defense Ships, often with identical designs. It uses these 2 types of ships in vastly different roles. Attack Ships are used to attack other empires and to explore the galaxy. Defense ships are used for... umm... I don't really know.
Maybe roles such as planetary defense and intercepting enemy ships that enter their space?
[ May 20, 2002, 15:25: Message edited by: Imperator Fyron ]