You can follow SharePoint feeds on the Newsfeed tab. A feed is a stream of content that you follow. You can also tune in to specific sites and documents by clicking the Follow button. The Follow button is in the upper-right corner of a site and in the drop-down list when you click the ellipsis next to a document.
The Newsfeed page includes the following feeds:
Following: The updates of documents, sites, and people you follow.
Everyone: All the updates from every person using SharePoint.
Activities: All your activities within SharePoint.
Likes: All the things you have liked. As the community rates content by clicking the Like button, you can begin to find the best content without having to go looking in every nook and corner.
Mentions: All the posts where you were mentioned. Mentions are accomplished using the @ symbol and your username.
A different type of feed is called an RSS feed. An RSS feed is a feed formatted in a special way to be read by an RSS reader. Every app has the ability to display its data using an RSS feed.
A feed on the Newsfeed tab and an RSS feed are different. Both are feeds of data, but an RSS feed is designed for external applications to view SharePoint data, and the Newsfeed is a place for you to aggregate and view communication happening within SharePoint.