Source : WordNet®

functionality
     n : capable of serving a purpose well; "software with greater
         functionality"

Source : Free On-Line Dictionary of Computing

functionality
     
         Waffle for "{features}" or "function".  The
        capabilities or behaviours of a program, part of a program, or
        system, seen as the sum of its {features}.  Roughly, "the
        things it can do".  Generally used in a comparative sense,
        e.g. "The latest update adds some useful functionality".
     
        (1997-07-14)