In 2012 versions of Windows Server, both editions (Standard and Datacenter) offers the same features and are only differentiated based on virtualization rights, choosing between the two will be based on your virtualization strategy. If your strategy depends on a highly virtualized environment, Datacenter Edition would be an appropriate choice, as it provides you with optimum flexibility with its unlimited capacity for virtualization. If your strategy depends primarily on a physical environment, Standard Edition provides you with the same full features as Datacenter Edition, but with fewer virtualization rights.
With Windows Server 2016 though, features exclusive to the Datacenter Edition include Shielded Virtual Machines, software-defined networking, Storage Spaces Direct, and Storage Replica. Please click here for more information.