Source : Free On-Line Dictionary of Computing

design pattern
     
         A description of an {object-oriented design}
        technique which names, abstracts and identifies aspects of a
        design structure that are useful for creating an
        object-oriented design.  The design pattern identifies
        {classes} and {instances}, their roles, collaborations and
        responsibilities.  Each design pattern focuses on a particular
        object-oriented design problem or issue.  It describes when it
        applies, whether it can be applied in the presence of other
        design constraints, and the consequences and trade-offs of its
        use.
     
        {Home
        (http://st-www.cs.uiuc.edu/users/patterns/patterns.html)}.
     
        ["Design Patterns: Elements of Reusable Object-Oriented
        Software", Erich Gamma, Richard Helm, Ralph Johnson, and John
        Vlissides].
     
        (1997-07-21)