When I made my 404 error page for my website, I naively made it a "404 redirect" page.
A "redirect" means that when you land on my 404 page, in about five seconds it takes you back to the home page. This is an optional approach to how to use your 404 page.
Ever since, I have discovered that the Los Angeles County Museum of Art uses a 404 redirect, I feel much better about this decision.
When you land on the 404 error page for the Los Angeles County Museum of Art, it automatically takes you back to the home page and navigation.
So your 404 Error page can be static....or a redirect.
What do you think is best?
For Wordpress users I recommend this video titled, SEO WordPress Panda Fix - Webmaster Tools 404 Errors to learn how to create a redirect for a broken link or URL that you have changed.