Hunt groups allow more than one destination to ring at once or in sequence. If you are setting up your Hunt Group to ring in sequence, then each number will be in a different level.
Within a hunt group, destinations are arranged into levels. All destinations within a level are rung at once. If none answer, they stop ringing, and all destinations in the next level are rung, and so on. A fail-over destination can be set as a last resort if the call does not get answered by any of the configured destinations.