RSS is a way for you to stay updated with websites you like. Instead of you having to go to websites to see if a new post or a new article has been added, you can use RSS (Really Simple Syndication) to get them to tell you every time they have something new.
RSS is a system whereby websites update information using a 'feed' comprising just the headlines, and important stories. By using special RSS-reading software on your computer, you can receive these instant updates directly.
An RSS reader automatically updates itself with the latest items from the sites you tell it to watch, so it's always fresh. You don't have to go from site to site, or constantly click the refresh button to know what's been published by the sites you frequently use. It sounds complicated but in practice it is very simple and instead of going through all those newsletters or visiting websites, you just open your RSS reader and scan the headlines from your chosen sites. If something catches your attention, click on the link and the full story is displayed. This way you can monitor multiple websites from one convenient browser, and customise it so that it only displays material and content that you are specifically interested in.