The content store selector provides a mechanism to control the store used for the content
file associated with a particular content item.
By applying the cm:storeSelector aspect and setting its cm:storeName property to the name of a selectable store, the content will be automatically moved from its current location to the new store. The store does not, therefore, store content itself, it defines and manages those stores that are available for selection.
This allows storage polices to be implemented to control which underlying physical storage is used, based on your applications needs or business policies.