Why? Well, because a password is needed, or the site belongs to a private network of organizations. You probably think that if it doesn’t show up on these search engines, then it doesn’t exist, wrong! Believe it or not, there are things on the web that will never show up on your traditional search engine, no matter how hard you may try.
When you go online to search for something, you either go to search engines such as Google or Bing.