Can someone explain what RSS Feed is?  

RSS is a standard format for news feeds. Basically, this means that it's like a constantly updated headline checker: you subscribe to a feed via your RSS software (locally on your PC) and that software checks the feed regularly. When the web site, blog or whatever you are subscribed to is updated, your RSS software spots the change, updates and notifies you. Its purpose is to keep you updated on sites without having to visit them all individually: you can have a whole ton of RSS feeds being checked by one piece of software.

Usually, RSS software runs in the background and often has a little 'headlines' bar that runs across part of your screen. That tells you when something is updated and (usually) allows you to click the update to be taken to the appropriate site. The update information and URL to go to are included in the RSS feed, in a standard format.

Does that make sense?

RSS is a family of Web feed formats used to publish frequently updated works—such as blog entries, news headlines, audio, and video—in a standardized format.[2] An RSS document (which is called a "feed", "web feed",[3] or "channel") includes full or summarized text, plus metadata such as publishing dates and authorship. Web feeds benefit publishers by letting them syndicate content automatically. They benefit readers who want to subscribe to timely updates from favored websites or to aggregate feeds from many sites into one place. RSS feeds can be read using software called an "RSS reader", "feed reader", or "aggregator", which can be web-based or desktop-based. A standardized XML file format allows the information to be published once and viewed by many different programs. The user subscribes to a feed by entering the feed's URI (often referred to non-technically as a URL) into the reader or by clicking an RSS icon in a browser that initiates the subscription process. The RSS reader checks the user's subscribed feeds regularly for new work, downloads any updates that it finds, and provides a user interface to monitor and read the feeds.