What Does A Feed Do?
As stated previously, feeds are most commonly used with web sites that are frequently updated, like blogs and news sites. By creating a ‘feed’, the author can easily syndicate his or her content in a format that others can access by subscribing to the feed. When the author changes the content on the site, it’s automatically updated on the desktop or web page of every single person who subscribes to that feed.
Feeds are most commonly referred to as pulling, rather than a pushing technology. Pushing technology is broadcasting a message and hoping that someone will come by your website or your television station to listen to it. RSS is pulling technology because visitors subscribe to your message and can retrieve it whenever they want.
A person on the internet has access to a large body of knowledge, but they can use pull technologies like RSS to engage in people, resources and information when the need arises. This in itself is a shift towards a “just in time” type of approach to concept understanding.
Imagine that you have a list of bookmarks in your favourite web browser that you visit regularly. Sometimes the content on these sites are updated, other times they are not. What if your bookmarks let you know when these sites have been updated? Then you wouldn't have to waste time with the ones that were not updated. That is what feed aggregator can do for you.