Do 404 errors hurt your search engine ranking results?

Do 404 errors hurt your search engine ranking results?

Google's John Mueller commented in a discussion forum on sites that have many 404 pages:

"Having a large number of 404's on a site is generally not a problem for us, especially if the 404 page helps the user to find related entries within your site.

Using a 404 (or perhaps, if you're certain that the page will be gone forever, a 410) is a good idea because it helps us to remove the old entries from our index over time."