RSS is the abbreviation of Really Simple Syndication. What it is simply, is a document of your website that is created by your site software in a format that is able to be read by a feed-reading program. Your website is built in such way that a web browser can read the information on the site and that is what you see when you visit the site in a browser such as Internet Explorer, Firefox or Safari. The RSS feed is just another format of the website content that can be read in a different way.
When you look at the raw rss feed it has all kinds of code like pieces to the information. These code tags tell the feed reader what that content is and how to display it in the feed reader.
One of the great benefits of RSS feeds is that rather than having to go back to a website to read the new content that has been posted a person can subscribe to the site via a feed reader and read it with their other feeds from other sites in a mobile device, on their browser or in any other feed reader. T his makes it a lot more efficient to keep up on a number of blogs and websites.