If you lack the concept of threads, this is a lecture that I definitely recommend! It's still a long way to go to finish it, but it's a lecture that I really don't regret spending money on! How great it would have been if I had someone like this as my teacher..! Anyway, I highly recommend it! I'm looking forward to the next lecture! I enjoyed the security lecture too~ I would appreciate it if you would hold a lecture related to DB in the future!