What is a RSS Feed

In the context of WordPress, 

An (RSS) feed, often called RSS (Really Simple Syndication) is a stream of posts or comments that is updated when new content is published. 

RSS is a useful feature to have on your website because it allows users to easily keep up-to-date with any new content you create. It can increase your readership and helps to improve user engagement.

Finding your RSS feed URL within WordPress is simple; it is the name of your website with “/feed” added to the end of the URL. You’ll then be taken to the XML file that displays the feed in its raw form.

The XML file contains details about every piece of content a site has published. Every WordPress blog has multiple feeds. The main feed mentioned previously and filtered versions of the feed created by the categories you apply to the content you create. 

Reading an RSS feed requires an RSS Reader

There are two different ways to use RSS feeds on your website.

  1. Publishing RSS feeds of your own contentYou can promote your own RSS feeds, encouraging users to subscribe with buttons and links.
  2. Publishing RSS feeds of other people’s contentYou can also publish RSS feeds from other websites and news feeds on your website. You’d create those links manually, or use a plugin.

Source: Wikipedia WPBeginner RSS.com