Key Notes (or Guided Notes) give a brief overview of the day's lesson, with a framework for all important information (such as formulas, concepts, and main ideas) provided for the student. This allows the teacher to make expressly clear the main ideas and concepts of the lesson, and spares the student the arduous task of transcribing large amounts of material from overheads or the chalkboard.
For more information on this topic please see:
Iowa State University's
website for faculty