what does "feed" mean in the blog section?

Tweet

I'm confused by this. I use blogspot, & I saw that it says "Atom" at the bottom of it, so I put this as the "feed", but when I clicked it to check, there was nothing. I think I'm doing something wrong. Can someone help? I thought "feed" was where someone else supplies your content & it's fed in, but I supply my own. Thanks to whoever can help. Also, "feed" has the red star by it when signing up your blog, so I thought it was mandatory...? Thanks, Bea http://homemadecash.blogspot.com