The fine line between presenting and teaching

As part of my regular profession I am currently preparing material for two 1.5 hour courses. That made me think about the difference between a regular presentation (if that exists at all…) and teaching. For my courses I have been given material that formed these courses as a fully automatic web based training. Of course, the slides fall through in most aspects of a great presentation; far to much content for a presentation, not enough detailed for a documentation. But under the context of teaching, what is to be different, what should be the same?