To understand JavaScript’s event handling model, you must first think about the things that can actually happen on a Web page. Although there are many different things you can do with the browser, most of these have nothing to do with Web navigation.
When you save a page as text, print a page, or edit your hotlist, you are not actually navigating the Web. In these cases, you are using some of the graphical capabilities of the browser, which are independent of the Web.
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