There are no explanations for those who don't know the basics of HTML, and even if you do, you'll often see mistakes. Sigil is currently at version 1.3.0, and the lecture is based on 0.7.4, so the design and functions are different, but it's not that difficult to follow, but it would have been nice if there had been additional explanations later, but there isn't. And in the beginning, there are parts where it stutters while talking and then goes somewhere else and comes back, but the coughing in the middle was not edited at all until the end. If you think of it as a video sold for money, it's insincere, but the quality is such that you should just endure it because it's free.