RSS (Really Simple Syndication) allows users to subscribe to frequently updated content like blogs and news sites through feeds that provide headlines and summaries of new articles. When subscribed, these feeds can be accessed through an RSS reader or aggregator to keep track of updates from multiple sites in one place across devices without needing to visit each site individually. Creating RSS feeds involves publishing simple text files from a blog or site that contain standard XML elements informing aggregators where to find new content updates.