You use RSS (Really Simple Syndication) to syndicate or subscribe to the feed of a website, blog or almost any media content online (not just articles, it can be music, video or almost any digital media). By syndicating you subscribe to the feed of the site which means you do not have to go visit the website to read the latest content. Instead you use feed reading software or a website to read the latest articles. Instead of going to each of your favourite sites individually you can collect all the feeds of the sites (provided they make them available) in one place. The purpose of syndication is to therefore make it more efficient for you to consume your favourite content.If you are not into the technical side of the Internet your don’t need to know much about XML. It’s basically the formatting language that software and websites use to distribute the content to your feed reader. If you know nothing about HTML then you probably don’t really need to know much about XML either. Just understand that behind syndication is the language XML.

For a more detailed coverage, i strongly suggest you to check my mentor Yaro Storak’s article What is RSS and How Do I Use It?”