Comparison Thinking (reason through analogy)
When you make decisions and judgement calls based on what you or others have experienced. An easy mode of thinking but also offers no innovation or large changes.
First Principles Thinking (new perspective)
When you take a problem and break it down to its fundamental parts and truths, you think of a way in solving it in a new and innovative way. A harder mode of thinking, but does offer better results, is far more effective and creates recognizable change.