Years ago, in the stone age of computing (~1990), I used to access an X-Window environment on my Sun Sparc5.  Pretty cosmic stuff for the time, and gave a lot more control over the UNIX operating system than if a non-systems person like me would have through the command line.  The applications, such as Asterisk (an old office suite for UNIX), were ahead of the times, giving us a very good idea of what the future held in a client-server world.

The UNIX environment allowed us to operate our workstations either in stand-alone mode, or fully networked into a mesh of other workstations.  Any of the workstations interconnected in our "Internet" could operate as an application server for any other workstation on the network.  All you needed to know was the IP address (or later domain name) of the workstation, and be able to pass the security check. 

This accomplished a number of objectives.  It ensured that losing one work station would never kill the entire network of applications.  It allowed a certain level of efficiency to better utilize available resources (e.g., unused resources on workstations were used by server applications).  And it allowed individual users to log in from any workstation and execute the applications they needed to do their work - location independent from their home workstation.