you are correct that you CAN - but who does. That's no longer considered best practice. The arugment these days is that it's a lot easier to manage css if it's in a separate file, same with js, etc. So none of the serious web developers actually do anything inline anymore. The time it would take to convert a "best practice" website with separate files for html, css, js, etc. is just not worth it. The point he's making is still valid - why not have the option for something static.