The publisher of a RSS enabled site provides you with a RSS feed.
This feed is a file on the internet that contains information about the most recent items and other changes on the website.
A so called RSS reader fetches this file from the internet and checks on a regular basis the content to check for you if new items were published. As soon as there is new information the reader shows this to you. After that it's you who decides whether or not to visit the information that was talked about in the feed. In this way you only have to decide to visit a site if there is new infromation you are interested in.
So the use of RSS helps you to reduce your waste of time.
N.B. You recognize RSS or web feed enabled sites by icons like this
