I uploaded a file called, say, test.html.
it has an element within...

so, I created a sub-folder called "images" and loaded "logo.jpg" into it. It doesn't work! Can I do this kind of thing?
I suppose in general can I put links to other documents/images inside a html file?
Even more generally - how do you tell where resources will be from the standpoint of a HTML link. For example, I have seen forum messages on the moodle site that link to external resources. How is that accomplished?