What is the Deep Web?
Unlike the surface web, the deep web is not searchable by standard web search engines. Most content is protected by user IDs and passwords. It can include electronic health records, social media posts, email accounts, and pay-to-access websites.
There are more than 200,000 websites on the deep web. These sites often block search engine bots from accessing their content. In addition, fee-for-service sites require customers to create a user id and password. This makes access to their content difficult for free users.