Load and execution sequence of a web page?

Question

I have done some web based projects, but I don\'t think too much about the load and execution sequence of an ordinary web page. But now I need to know detail. It\'s hard to

Answer 1

The chosen answer looks like does not apply to modern browsers, at least on Firefox 52. What I observed is that the requests of loading resources like css, javascript are issued before HTML parser reaches the element, for example

What I found that the start time of requests to load css and javascript resources were not being blocked. Looks like Firefox has a HTML scan, and identify key resources(img resource is not included) before starting to parse the HTML.