What does the expression 'RSS' mean?

All the answers before me are correct, but I would like to add more about how you would actually use RSS. RSS is a method by which a "feed" of information can be distributed to people on the internet. Many web browsers will show an RSS icon when a website you are visiting has available RSS feeds. You can "subscribe" to an RSS feed in an application called a feed reader or feed aggregator. This can either be a program on your computer/phone/tablet or a web-app that you log into. I don't think "subscribe" accurately describes how it works, because you don't have to sign up for anything. You just add the feed to a list and that's it. When you open up your feed reader, you are presented with all the latest updates from all the various feeds you have added, as well as archives of previous articles/entries/content. This saves you from having to go around and check many different websites on the off-chance there might be something useful there. Often, information can be read directly in the feed reader without even having to go to any websites. Feeds are usually text-based, but they can include pictures, and multimedia content. Feeds that deliver regular audio-based items to listen to are typically called "podcasts". MP3 player software such as iTunes can automatically download podcast audio onto an MP3 player. It is also to receive video podcasts.

RSS is the acronym used to describe the de facto standard for the syndication of Web content. RSS is an XML-based format and while it can be used in different ways for content distribution, its most widespread usage is in distributing news headlines on the Web

All the answers before me are correct, but I would like to add more about how you would actually use RSS. RSS is a method by which a "feed" of information can be distributed to people on the internet. Many web browsers will show an RSS icon when a website you are visiting has available RSS feeds. You can "subscribe" to an RSS feed in an application called a feed reader or feed aggregator. This can either be a program on your computer/phone/tablet or a web-app that you log into. I don't think "subscribe" accurately describes how it works, because you don't have to sign up for anything. You just add the feed to a list and that's it. When you open up your feed reader, you are presented with all the latest updates from all the various feeds you have added, as well as archives of previous articles/entries/content. This saves you from having to go around and check many different websites on the off-chance there might be something useful there. Often, information can be read directly in the feed reader without even having to go to any websites. Feeds are usually text-based, but they can include pictures, and multimedia content. Feeds that deliver regular audio-based items to listen to are typically called "podcasts". MP3 player software such as iTunes can automatically download podcast audio onto an MP3 player. It is also to receive video podcasts.

RSS is the acronym used to describe the de facto standard for the syndication of Web content. RSS is an XML-based format and while it can be used in different ways for content distribution, its most widespread usage is in distributing news headlines on the Web

RDF Site Summary, but often misquoted as Really Simple Syndication; is the set of web formats used to publish frequently updated information such as blog's news feeds etc. and allows automatic syndication of content. Once a user subscribes to the content the RSS reader application automatically checks for updates on a user defined timescale.

RSS (Rich Site Summary) is a format for delivering regularly changing web content. Many news-related sites, weblogs and other online publishers syndicate their content as an RSS Feed to whoever wants it.

Really Simple Syndication - it's a method of distributing web content like news and blog feeds.

RSS (Rich Site Summary) is a format for delivering regularly changing web content. Many news-related sites, weblogs and other online publishers syndicate their content as an RSS Feed to whoever wants it.

Really Simple Syndication - it's a method of distributing web content like news and blog feeds.