RSS (Really Simple Syndication) is an XML format used to publish frequently updated content like blog posts or news headlines. RSS feeds allow websites to broadcast content to users through RSS readers, which are programs that check for updates from followed websites and compiles the new content in an easy-to-read format. Creating an RSS feed involves publishing simple text files on a website that describe metadata like titles, summaries and links for updated content in the standardized RSS format so that it can be read by RSS readers and shared with other users.