An RSS (really simple syndication) feed is a clean way of getting the content from a frequently updated source, such as a blog, or news site with just the key information.
Check out the Zapier blog RSS feed here to see how an RSS looks when you visit one on your browser.
To get started Triggering from an RSS feed from Zapier, you'll need to choose "RSS by Zapier" as your Zap's Trigger and then you'll be able to connect to your feed in step 4 of your Zap.
You'll need to enter the URL of your feed into the "Feed URL" field. If your feed is private (and requires a login to view) you can enter your username and password here too. If not leave those fields blank.
If you are using RSS as the Action for your Zap, you'll be able to create your own feed URL and customize the content that will be populated within that feed in step 5 of your Zap.