These digital repositories – often referred to as digital archives or archival gateways – pull together and make available digitized archival collections from many different libraries and archives. This type of system interoperability – sharing digitized collections among multiple repositories – is possible due to metadata standards like Dublin Core.
They include both types of freely usable digital assets, or one of these types. Your must review each item record to determine the type of license, and the license requirements if Creative Commons.
They include both copyrighted and public domain works. You must review each item record for its respective rights information.