Richard Byrne posted this article on his blog.
This is a great explanation of each type of web document. There are some great examples at the bottom of the chart (Google Spreadsheet).
Here is a direct link to the chart:
There are some really intelligent ways to search Google. I take for granted the multitude of options for searching. Everyone “Googles”, here are some ways to dig deeper and smarter:
http://www.google.com/intl/en/help/features.html
Related Articles Search Google Docs, Emails And Sites