"RSS" stands for "really simple syndication," and it's a simple and standardized method of content distribution that helps you stay up to date with your favorite blogs, websites, and other sources of content. Publishers make an "RSS feed" available which can be subscribed to using an RSS reader app, where any newly published content will pull through to.
Feedly offer a straightforward web-based RSS reader. If you prefer a native application and are on macOS or iOS, then I personally use NetNewsWire. Here's what my NetNewsWire app looks like:
My RSS feed can be found here and by putting that link into your RSS reader app of choice, you'll be able to automatically see when I've published a new blog post without needing to check the website.