To be honest, I don't want to sound bad, but he seems to state the obvious thing which is available in Wikipedia or first page of google. So, I don't think he

To be honest, I don't want to sound bad, but he seems to state the obvious thing which is available in Wikipedia or first page of google. So, I don't think he provide rapid, in-depth information... . However, I do think he provide good information for layman like me. I have watched lithography, opensource related videos and they were general knowledge.