What does soft 404 error mean?

[anjali raghav]

I see this quiet often in SEO discussions, blog posts, etc.

Soft 404 error

But what does that really mean? Is there an hard 404 too? How are these different?

[lishmalinyjames]

A soft 404 is a URL that returns a page telling the user that the page does not exist and also a 200 (success) status code.