What is a dead link? What does a dead link mean?

What is a dead link? What does a dead link mean? Simply put, a dead link refers to a link that was originally normal but later became invalid. When a dead link sends a request, the server returns a 404 error page.

Broken links occur in the following situations:
1. Dynamic links become dead links when the database no longer supports them.
2. A file or web page has been moved, causing the link to it to become a dead link.
3. The web page content is updated and replaced with other links, and the original link becomes a dead link.
4. The website server settings are incorrect.
From the user's perspective, dead links and incorrect links behave the same way, so generally we don't need to distinguish between dead links and incorrect links.
As SEO website optimizers or webmasters, we must avoid dead links on our websites, because the number of dead links can be used to evaluate the authority of a website.