An open-world is a play area inside the game that is either endless or very large. Skyrim is an example of a very large map. It had 8-9 holds(i can't remember) and many many many many manyyy places to conquer. Minecraft is an example of an endless map. On the PC edition is is endless. On the Xbox360 and PS3 edition of minectaft, it is a large scaled world but not open.