RSS allows users to subscribe to frequently updated content like news headlines and blog posts from multiple websites. The content is collected into RSS feeds that can be read through an RSS aggregator, which compiles feeds from different sites into a single location. This makes it more efficient to keep up with new online content than visiting individual websites. RSS works by websites publishing simple text files that use XML formatting to define updates. Aggregator software can then read these RSS feeds and display the new content to users.