Is DAI backed by Ethereum?

I've heard DAI mentioned quite often in discussions about cryptocurrencies. And I know Ethereum is a major player in this space. So, I'm just curious, is DAI backed by Ethereum? I mean, does it have some sort of direct or indirect relationship with Ethereum? I'm trying to understand the underlying mechanisms and the relationship between these two entities. Can you explain it to me in a way that's easy to grasp for a non-expert like me?