task one
  similarities: the purpose of  the presentations is  teaching. the purpose and conclusion are clear.
difference:  the first speaker wrote points on the board and spoke slowly and clearly. The speech was formal. There were many details in the speech. 
the second presenter face to a group audiences.  He interacted with audiences successfully.   He didn't use any visual aid. He spoke a long time for illustrating one point. His gestures are varies.


The two presentations are totally different style. Both of them are good for me. I can get some  information from the first person. But I prefer the second one: He is very humor. He asked questions and know how to grab audiences attention. He teach us how to bring life into a speech by his speech. I think the audiences will  never forget "tell a story, make a point."