RSS (Really Simple Syndication) allows users to subscribe to frequently updated content like news websites and receive headlines and summaries. RSS readers (also called aggregators) collect RSS feeds from different sources in one place, letting users view updates from multiple sites in a single location. Aggregators offer options like viewing full articles or just headlines and help users efficiently keep up with subscribed content. Publishers can also create RSS feeds on their websites by following XML standards to describe updates and enable readers to detect and interpret the feeds.