Windows Server 2019 Downgrade & Down-Edition Rights
Downgrade and down-edition rights simplify application migration scenarios for customers by allowing them to license the newest Windows Server product, then run an earlier version and/or down-edition of Windows Server to support legacy business applications that have not yet migrated to the latest technology, until they are ready to migrate to the purchased Windows Server license. Then, once they are ready, they can migrate to the purchased license.
windows server
