RSS stands for Really Simple Syndication and is a popular way to automatically send updates to users who have subscribed to your RSS feed. RSS feeds can be read by most modern web browsers, or by software designed to specifically reed RSS feeds.
For example, all the major news sites provide RSS feeds for their main articles. You can subscribe to such a feed directly using your web browser. Your browser then periodically checks the feed for updates, automatically downloads the new articles, and then notifies you that updates are ready to view. So in essence, new information is automatically sent to you.
Your web site can publish an RSS feed to send information to subscribers. Let’s say that you are a realtor, for example. Every time you add a new property listing to your web site, the RSS feed can be automatically updated. Then all the users who have subscribed to the feed will get notified of the new listing. Or, if your web site has a calendar of events, then every time you add or update an event, your RSS subscribers will be notified. This works great for content such as recent news, software updates, or product announcements.
Conversely, you can add content to your site automatically by subscribing to and embedding an RSS feed into your web site. Say, for instance, that you want to show recent news headlines related to your industry. You can find an RSS feed that publishes this information, and then automatically embed it into your web site. So users will see the articles that are sourced externally, directly in your own web site. This is a good way to add external content to your web site.