Broken links, dead links or Linkrot are those URLs which are not available anymore and lead to nowhere. This problem might happen for many reasons. For example, they probably have moved form their original place or have been replaced by new information. This can be a very important issue for everybody who uses the web. In fact, broken links are one of the major parts of the opaque web as well. If you have a favourite links collection on your own web browser you probably have already noticed that how quickly these links getting out of date and you need to keep your list up-to-date constantly.