Yes... Thank you. I'm happy to see that you're following along well even though it's your first time. Please familiarize yourself with the parts I lectured on and refer to the sites I provided to gain more in-depth knowledge. In particular, if you go to the official Hadoop website and study various terms and knowledge, it will broaden your perspective on Hadoop and big data. Please also refer to foreign sites in the middle of the lecture notes. Also, look at the parts of the Korean website where Hadoop sites are organized here and there. Of course, you won't have a deep understanding, but if you search carefully, there are useful sites. If you want a deeper understanding, it would be good to study with an English original book. If you understood my lecture, it would be easy to read the original book. Even I, who is not good at English, am reaping the fruits of the time I spent struggling to learn. From wonjun1995. Thank you for the good fruits. Study hard and become a Hadoop expert. I'm cheering you on from Toronto!!!!