(Advantages) When I only heard a vague explanation of the service, I didn't understand it, but when I followed along and saw how it was used in an actual project, I understood it well. I learned how to find and use official documents. The teaching ability is decent. (Disadvantages) The sound is small. Even when I turn up the laptop speaker to the max, it's small, so it requires a lot of concentration. It's a shame that there is no EC2. I think the price is a bit expensive.