The term "RSS" (Rich Site Summary) is still sometimes used to refer to web feeds in general,  including web feeds with a format different than RSS. For example, the Blogspace description of using web feeds in an aggregator is headlined "RSS info" and "RSS readers" even though its first sentence makes clear the inclusion of the Atom format: "RSS and Atom files provide news updates from a website in a simple form for your computer."

RSS is a family of Web feed formats used to publish frequently updated works—such as blog entries,  news headlines, audio, and video—in a standardized format. An RSS document (which is called a "feed", "web feed", or "channel") includes full or summarized text, plus metadata such as publishing dates and authorship. Web feeds benefit publishers by letting them syndicate content automatically. They benefit readers who want to subscribe to timely updates from favoured websites or to aggregate feeds from many sites into one place. RSS feeds can be read using software called an "RSS reader", "feed reader", or "aggregator", which can be web-based or desktop-based. A standardized XML file format allows the information to be published once and viewed by many different programs.

The user subscribes to a feed by entering the feed's URI (often referred to non-technically as a URL) into the reader or by clicking an RSS icon in a browser that initiates the subscription process. The RSS reader checks the user's subscribed feeds regularly for new work, downloads any updates that it  finds, and provides a user interface to monitor and read the feeds.

RSS formats are specified using XML, a generic specification for the creation of data formats. Although RSS formats have evolved since March 1999, the RSS icon first gained widespread use between 2005 and 2006.