RSS feeds, sometimes known as “syndicated feeds” or “news feeds” are losing popularity, for reasons that escape me. I really like RSS. It allows you to subscribe to content that is published on a site without having to go to the site itself to check if new stuff has been posted. To subscribe, all you need is a news aggregation service/app, which collects all of the feeds and presents them in one place. You check your aggregator every day instead of going to several different sites.
RSS readers can be applications you install on your device or sites that you log into. My favorite used to be Google Reader. That went belly up in July, 2013, much to my annoyance. Now I use the Flipboard app and feedly. Learn more about RSS in plain English.