Strategy IO game can be real-time and step-by-step. In the first case you have to be as smart as fast. In the second case — it’s more a logic game, than a strategy. Anyway, strategy is a game where you control high scale events, such as ancient war, sea battle, or intergalactic conflict. Usually you have some army, buildings, and theater of operations. In most games you can upgrade your buildings and troops in the cost of come resource. Also you can train new troops or build new buildings. In strategy game you usually observe all of the action and control your units from far above freely moving the camera around.