Source: La Trobe University. (2010, February 10). Why can't I just Google? [video]. YouTube.
Source: La Trobe University Library. (2015, January 22). Can I use Wikipedia? [video]. YouTube.
Subject directories are organized indexes of subject categories where you can browse through lists of web sites created and maintained by actual humans!
Here are some examples:
Grey literature is often in the form of government or scientific reports, conference proceedings or other research data that traditionally has not been easy to locate.
Good web searches can now more easily locate this kind of material.
Watch this video to find out more about grey literature.
Source: Western University. (2012, September 4). Grey literature tutorial [video]. YouTube.