Please watch the following video. After you watch the video, Please summarize it include all relevant information and tell us what concepts you are comfortable with and which concepts are still challenging if any? 

https://www.khanacademy.org/science/health-and-medicine/human-anatomy-and-physiology/introduction-to-immunology/v/types-of-immune-responses-innate-and-adaptive-humoral-vs-cell-mediated
Please elaborate and write all relevant information, brief posts without all relevant information will means less points.