That's just their corporate propaganda. For the most part, it's Bing with some additional features.

Their crawler (DuckDuckBot) doesn't have much of an impact on the search results, it's mainly used to provide instant answers. [1]

[1]: https://seirdy.one/2021/03/10/search-engines-with-own-indexe...

Do they list their "sources"?

It reads like they are saying a website = source, and the hyperlink for the sources is dead.