I started learning Unreal Engine with Youtube tutorials, and while there's a ton of videos out there with great information, I never really felt like I was able to understand how some of these features worked. This textbook does a great job going into detail about these features of Unreal like the script editor and Niagara. And since this is a pdf/ebook I can go back and quick search things I may need to refresh my knowledge on. And for someone who is still learning Unreal, the diagrams are incredibly helpful since they're screenshots that focuses on each panel or input that's being explained. For someone who doesn't remember anything from high school algebra, the diagrams that explain different vector operations in a visual manner are such a nice touch. Unreal is pretty scary to new users who aren't very familiar with the system, and this book helps make it a lot less scary.