You may think that the Internet is a huge resource of information, but in fact what most of us see is just one link in a very long chain of underground websites and unseen content. World Wide Web as we know it represents just 4% of networked web pages and the remaining 96% of pages make up what many refer to as the Invisible Internet, Invisible Web or Deep Web which is the part of the Internet that is hidden from view.
4% of World Wide Web content is the surface web, also known as the Visible Web, it is content that can be found using search engines such as Google or Yahoo. It is under constant surveillance by the government.
96% of World Wide Web content is the Deep Web, also known as the Invisible Web, it is the content that cannot be indexed by search engines. And it is hard to keep track of. The Deep Web is estimated to be 500X the size of the Surface Web.
How to find the Invisible Internet and how to access it?
In order to access the Deep Web, you need to use a dedicated browser, TOR (The Onion Router) is the most commonly used, but other options such as I2P and Freenet offer an alternative solution. Information on the Deep Web cannot be accessed directly. This is because data is not held on any single page, but rather in databases, which makes it difficult for search engines to index. Files are shared through any number of computers connected to the Internet that hold the information you need. This is known as peer-to-peer networking. This method of sharing encrypted data makes it difficult for your location and the kind of information you access to be tracked or monitored.
Is it legal?
Yes. You use it as you would any other Internet browser. Many people are now beginning to use TOR as a way of maintaining their privacy whilst online. Due to the anonymity that TOR offers, the Deep Web has also become a popular nesting ground for criminal activity.
The Deep Web is not illegal. It is basically the storage of online information that people do not want to share publicly and includes material from universities with classified research, police restricted information, industrial secrets, hospitals with medical records, etc. Typically anything that requires an account and credentials to gain access to it falls within the scope of the Dark Web.
– Innovation Report: Anonymous Networks and Darknet by INTERPOL Innovation Center on Sept. 2018