Source : Free On-Line Dictionary of Computing

declarative language
     
        A general term for a {relational language} or a {functional
        language}, as opposed to an {imperative language}.  Imperative
        (or procedural) languages specify explicit sequences of steps
        to follow to produce a result, while declarative languages
        describe relationships between variables in terms of functions
        or {inference rule}s and the language executor ({interpreter}
        or {compiler}) applies some fixed {algorithm} to these
        relations to produce a result.  The most common examples of
        declarative languages are {logic programming} languages such
        as {Prolog} and {functional language}s like {Haskell}.
     
        See also {production system}.
     
        (1994-11-23)