Windows Server Datacenter Edition is the Microsoft server operating system optimized for server consolidation, large data warehouses, OLTP (online transaction processing), and line-of-business applications that require the highest levels of scalability and availability. It's ideal for highly virtualized and software-defined datacenter environments. It supports unlimited operating system environments or Hyper-V containers as well as unlimited Windows Server containers. Features exclusive to the Windows Server Datacenter edition include Shielded Virtual Machines, software-defined networking, Storage Spaces Direct, and Storage Replica. The Datacenter edition is licensed on a Core/CAL model and requires Windows Server CALs.