You load the software on all the PCs on your network and Network Magic automatically creates a managementlayer that bridges the interoperability gaps between disparate network devices.
Typically this means owning the managementlayer, through virtualization, though of course companies like Cisco make a case for the network among computers as the critical part.
Putting the bulk of computing and storage in the data center has other perks for IT management: It creates a centralized location for software upgrades across an entire organization and puts a layer of network security between users and sensitive data--a lost thin client laptop, for instance, doesn't contain private information, and so doesn't pose a threat of causing a data breach.