TOR, short for The Onion Router, is an obscure routing network that allows anonymous access to the “darknet” – the vast, murky portion of the internet that cannot be indexed by standard search engines. Estimated to be 5,000 times larger that the “surface” web, it’s in these recesses where you’ll find human-trafficking rings, black market drug markets and terrorist networks
When used to describe a file sharing network, the term is often used as a synonym for “friend-to-friend“—both describing networks where direct connections are only established between trusted friends. Software such as Nullsoft’s Waste use this method. The most widespread “non-darknet” file sharing networks, such as BitTorrent, are not true darknets since peers will communicate with anyone else on the network. Darknet is also commonly used in a broader sense to describe any network which is non-commercial, that offers some level of anonymity and or obscurity. These networks usually make it less cost effective to uncover a user’s activities. Many darknets require software to be installed to access them. Popular darknets include Freenet and GNUnet (when using its “F2F topology” option). Almost all known darknets are decentralized and therefore considered peer to peer.
- Dark Internet, machines unreachable by other computers on the internet
- Deep Web, website content not indexed by search engines
- The Deep Web (also called the Deepnet, Dark web  DarkNet, the Invisible Web, the Undernet or the Hidden Web) is World Wide Web content that is not part of the Surface Web, which is indexed by standard search engines. It should not be confused with the dark Internet, the computers that can no longer be reached via the Internet, or with a Darknet distributed filesharing network, which could be classified as a smaller part of the Deep Web. There is concern that the deep web can be used for serious criminal activity. 
- Mike Bergman, founder of BrightPlanet and credited with coining the phrase, said that searching on the Internet today can be compared to dragging a net across the surface of the ocean: a great deal may be caught in the net, but there is a wealth of information that is deep and therefore missed. Most of the Web’s information is buried far down on dynamically generated sites, and standard search engines do not find it. Traditional search engines cannot “see” or retrieve content in the deep Web—those pages do not exist until they are created dynamically as the result of a specific search. As of 2001, the deep Web was several orders of magnitude larger than the surface Web.
Deep Web resources may be classified into one or more of the following categories:
- Dynamic content: dynamic pages which are returned in response to a submitted query or accessed only through a form, especially if open-domain input elements (such as text fields) are used; such fields are hard to navigate without domain knowledge.
- Unlinked content: pages which are not linked to by other pages, which may prevent Web crawling programs from accessing the content. This content is referred to as pages without backlinks (or inlinks).
- Private Web: sites that require registration and login (password-protected resources).
- Contextual Web: pages with content varying for different access contexts (e.g., ranges of client IP addresses or previous navigation sequence).
- Limited access content: sites that limit access to their pages in a technical way (e.g., using the Robots Exclusion Standard, CAPTCHAs, or no-cache Pragma HTTP headers which prohibit search engines from browsing them and creating cached copies.)
- Non-HTML/text content: textual content encoded in multimedia (image or video) files or specific file formats not handled by search engines.
- Dark fiber, unused optical fiber communications infrastructure
Darknet sites are hosted on regular servers, but to access them you need special software, usually something that encrypts all users’ traffic and allows them relative anonymity. Get set up with the right technology and presto: You can see a second, parallel Internet.
Dissidents around the world use Darknet services to avoid authoritarian forces. DuckDuckGo, a privacy-minded search engine, also runs a Tor-hidden service so users can search the web in complete anonymity. DuckDuckGo itself has no idea who’s typing the queries. Even the US military gets the need for a place to do everyday things in secret, apparently: Tor’s creation was sponsored by the US Naval Research Laboratory.
Plus, other alternative Internets are emerging, and they work quite differently from the Darknet’s anonymous drug dens.
WE SHOULD PROBABLY JUST START CALLING THE WEB THE SPYNET.