Minecraft wiki entry for World, associated text: Worlds are split into three dimensions, which are in turn composed of blocks of various sizes, usually either cubic or composed of one or more cuboids, or of flat plane images, all of which are arranged in a Euclidean grid. Fluids, entities and particles also exist within these worlds, and certain locations of the world can possess biomes and different levels of light. Blocks and entities can possess other attributes such as items, status effects and, by extension, enchantments. Various structures can also generate inside worlds (provided that the 'Generate structures' world option is turned on), sometimes containing chests with loot inside.