Rich site summary, originally known as RDF Site Summary and commonly called Really Simple Syndication, is a standardised method of publishing frequently-updated online media feeds.
Feeds of content are pushed out in the XML file format and picked up by users with RSS readers, often known as aggregators, which can be software, web- or mobile- based and come in both free and paid versions. RSS readers regularly ‘talk to’ the website they derive their feeds from and automatically update the feed with any newly-published content.
Advantages to publishers include letting them syndicate content to multiple places automatically and extending their reach beyond visitors to their website. Users save time by receiving all newly-published content direct to their readers without having to manually browse the relevant websites.