I was wondering if there are any available resources that describe how a browser\'s cursor executes Javascript.
I know it loads and executes tags when a page loads,
If you just stuff a block of HTML containing script tags into your DOM with "innerHTML", the script tags won't be executed at all. When you load stuff with something like jQuery, code in that library explicitly handles finding and executing the scripts.
It's not precisely accurate, but you can basically think of the processing of a tag as if the whole contents of the tag (i.e., the script body) were executed with eval(). If the script declares global (window) variables, then old values are overwritten.
Script tags are processed in the order that they appear. Of course the code inside the script blocks may be set up so that what it does upon initial execution is to defer the real processing until later. Lots of jQuery setup/initialization code will do that.