Cornell Notes use a two-column note taking approach. Fold (or draw) a vertical line down the left side of your note paper about three inches from the left side. The primary function of this style of notes is to organize your ideas into main or broad ideas and then more specific examples, definitions, or analysis. On the left hand margin, you record your main ideas; then on the right hand side, you record your examples, definitions, and analysis of those main points. The advantage of the Cornell system is that it easily allows for the note-taker to study or review their material later on. You can fold over one side of the paper so as to keep the examples or defintions covered, and easily quiz yourself.
Mind-mapping is a note-taking strategy that works best for recording relational material, or showing relationships between certain topics. The great advantage of mind-mapping is the appeal to the visual learner, that the organization easily shows how the note topics and subpoints relate to one another.
All three of these strategies are similar in the way they organize information for the note-taker; however, the different formats all address specific purposes for taking notes, whether it be to organize main idea or depict relationships between the topics.
Outlining is best suited for chronological material. The structure of an outlining notetaking system allows the notetaker to organize their material from broad topics to narrow.