Robert Entman provides an excellent analysis of framing as it pertains to selection and salience.
 

Framing essentially involves selection and salience.  To frame is to select some aspects of a perceived reality and make them more salient in a communicating text, in such a way as to promote a particular problem definition, causal interpretation, moral evaluation, and/or treatment recommendation for the item described.  (Entman, 52.  Emphasis in original.)

Frames, then, define problems - determine what a causal agent is doing with what costs and benefits, usually measured in terms of common cultural values,  diagnose causes - identify the forces creating the problem; make moral judgments - evaluate causal agents and their effects; and suggest remedies - offer and justify treatments for the problems and predict their likely effects.  (Entman, 52.  Emphasis in original)