A broken link is a link that points to a nonexistent object. It happens when a file, document or web page has been moved or deleted. Broken links degrade user experience, as a visitor does not receive the information for which he had come to the site for. A large number of broken links could adversely affect the position of the site in the SERP.
To avoid broken links, you can use the CMS. We also recommend that you install our free widget. It will warn you if your site has broken links.