KickstarterForum.org

What exactly is website authority in SEO ranking?

I hear this everywhere: "you have an authority issue."

But nobody explains what it actually means or how it works.

Is it defined by backlinks? If so, what kind link? traffic-sending backlinks, or just mentions/citations scattered across the web?

Or is website authoritysimply about having a high DR (Domain Rating) and similar metrics? I know they are third party but still asking...

Can anyone explain website authority in simple terms?