Lyoko is a virtual world contained within a Supercomputer within the Factory. In Rock Bottom however, it is stated by Aelita that Lyoko is constantly changing it's position on the Network, meaning either different parts of the Digital Sea flow into it at different times as it drifts across the Internet, or that Lyoko isn't actually housed in the super computer at all, but is instead run as a sort of server on the Internet managed by the Super Computer. This is divided into five separate sectors, all with their own unique features. The first four sectors are arranged around the fifth, like a star. Each sector is isolated from the others by the Digital Sea.