What is an RSS?

[chifan]

I have viewed a lot of website like XANGA, MSN, Google... I saw that there
is an RSS icon at the bottom of the page. What is it used for? Can anyone help me to answer this question?

 

[dmroeder]

Go to MSN.com and look at the top, right corner of the page (to the right of the search button). You will see RSS. Click on it and it will explain.