Google Reader is a very useful and simple application that make it easy to you to be updated with the new posts, news and any update add to the sites you chosen that support Atom and RSSfeeds with your Gmail account.
In simple way if you followed some blogs or subscribed in RSS feeds you can see what is the new in these sites by Google Reader “all in one place” instead of check each site separately
Example
here you can access to your Google Reader
finally:
I hope this to help you in keeping you in touch with useful sites
