Ok RSS feed means "Really Simple Syndication". I use them and they are nice. Basically there is a few dozen sites and blogs that I like to read well who has time to go to every one of them. When you subscribe it you can see all of your favorite sites in one easy reader. You have to have a reader to read them with. There are many different ones. The one I like and use is google Reader.

Here is how Google Reader explains it to new users:

Welcome to Google Reader

Google Reader helps you find and keep track of interesting stuff on the web. You can subscribe to your favorite websites, see what your friends are sharing, and keep up with what's popular. New content comes to your Google Reader when it's posted, so you don't need to visit individual sites.

Plus, Reader keeps track of which items you've read, so you only see unread items when you come back. If there's a dark blue border around an item, Reader is marking that item as read.

Here is the logo for RSS feed: