Google is one of DDGs backends, and the highest quality one at that. DDG does not have its own crawlers or index. Nor could it: those things cost hundreds of millions of dollars per year to run and maintain.
[Edit: apparently this is not true. DDG does not use Google, though it does use Bing and some other broad and narrow coverage search engines]
[Edit: apparently this is not true. DDG does not use Google, though it does use Bing and some other broad and narrow coverage search engines]