G.Q: Why would I want to put information on my web page that is not visible to the typical viewer?
I would want to put information on my web page that is not visible to the typical viewer because I might want to tell search engines and browsers about information like the language and the author, but not want the user to see it because it is not important to them. It is important to have metadata because it tells search engines things about the page that the user might search for. It also makes sure the broswer uses the right alphabet for the html. For example, if you type an html in Russian, you can't have the browser show the html as if it used the English alphabet.