When a link from your page lead to a 404 error (page not found), then it is called as broken link. Either you entered the URL as incorrect or the page have been removed recently. Do you know how broken links can harm your site, Google crawling and indexing webpages for display high quality search result to their users. But when your page having some broken links, it will clearly cause you rankings to suffer. By using this tool, you can check for any broken links in your website.