Source : WordNet®

workstation
     n : a desktop digital computer that is conventionally considered
         to be more powerful than a microcomputer

Source : Free On-Line Dictionary of Computing

workstation
     
         A general-purpose computer designed to be used by
        one person at a time and which offers higher performance than
        normally found in a {personal computer}, especially with
        respect to graphics, processing power and the ability to carry
        out several tasks at the same time.
     
        (1995-05-04)