Please find listed a  full definition of the egg production system as stated in the Australian Model Code of Practice for the Welfare of Animals – Domestic Poultry:

Cage Systems
Birds in cage systems are continuously housed in cages within a shed,

Barn Systems
Birds in barn systems are free to roam within a shed which may have vertical levels. The floor may be based on litter and/or other material such as slats or wire mesh,

Free Range Systems
Birds in free-range systems are housed in sheds and have access to an outdoor range;