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. For example, if you have a fast (and expensive) local disk, you can use this to store the files that you want to ensure are served for best performance; however, infrequently used files may be stored on lower cost, slower storage.