Each incoming link from an outside website acts as a vote of confidence for the website being linked to. If another website feels the content of another website is important enough to recommend its visitors to read it, search engines are alerted to that importance. Caution must be taken here that quality is much better than quantity. Incoming links from websites that are absolutely irrelevant can cause more harm than good. Search engines take a close look at the relevance between linking websites in order to keep websites from cheating the system.