Source : Free On-Line Dictionary of Computing

CONS
     
        {connection-oriented network service}

cons
     
        /konz/ or /kons/ [LISP, "construct"] A {Lisp} function which
        takes an element H and a list T and returns a new list whose
        head is H and whose tail is T.
     
        In {Lisp}, "cons" is the most fundamental operation for
        building structures.  It actually takes any two objects and
        returns a "{dotted-pair}" or two-branched tree with one object
        hanging from each branch.  Because the result of a cons is an
        object, it can be used to build {binary tree}s of any shape
        and complexity.
     
        [{Jargon File}]