Dead link
A dead link is a link on the world wide web that points to a webpage or server that is permanently unavailable. Dead links are commonplace on the Internet, but they are considered to be unprofessional.
The most common result of a dead link is a 404 error, which indicates that the page could not be found.
Dead links can also be a URL that points to another site that is unrelated to the content someone would search for (e.g., Search for Sports at ESPN.com, find pornography; Pornography is a common dead link subject.).
Dead links are commonly caused by Linkrot.