What Is the Darknet?
It is sometimes confused with the deep web, a term that refers to all parts of the Internet which cannot be indexed by search engines and so can't be found through Google, Bing, Yahoo, and so forth. Experts believe that the deep web is hundreds of times larger than the surface web (i.e., the Internet you get to via browsers and search engines).
In fact, most of the deep web contains nothing sinister whatsoever. It includes large databases, libraries, and members-only websites that are not available to the general public. The dark web (or dark net) is a small part of the deep web. Its contents are not accessible through search engines, but it's something more: it is the anonymous Internet. Within the dark net, both web surfers and website publishers are entirely anonymous. Whilst large government agencies are theoretically able to track some people within this anonymous space, it is very difficult, requires a huge amount of resources, and isn't always successful.
Darknet anonymity is usually achieved using an onion network. Normally, when accessing the pedestrian Internet, your computer directly accesses the server hosting the website you are visiting. In an onion network, this direct link is broken, and the data is instead bounced around a number of intermediaries before reaching its destination. The communication registers on the network, but the transport medium is prevented from knowing who is doing the communication.
Who Uses the Darknet?
Military, government, and law enforcement organisations are still amongst the main users of the hidden Internet. This is because ordinary internet browsing can reveal your location, and even if the content of your communications is well-encrypted, people can still easily see who is talking to whom and potentially where they are located. For soldiers and agents in the field, politicians conducting secret negotiations, and in many other circumstances, this presents an unacceptable security risk.
The darknet is also popular amongst journalists and political bloggers, especially those living in countries where censorship and political imprisonment are commonplace. Online anonymity allows these people, as well as whistleblowers and information-leakers, to communicate with sources and publish information freely without fear of retribution. The same anonymity can also be used by news readers to access information on the surface web which is normally blocked by national firewalls, such as the 'great firewall of China' which restricts which websites Chinese Internet users are able to visit.
Accessing the Darknet
The most popular way to do it is using a service called Tor (or TOR), which stands for The Onion Router. Although technically-savvy users can find a multitude of different ways to configure and use Tor, it can also be as simple as installing a new browser. The Tor browser can be used to surf the surface web anonymously, giving the user added protection against everything from hackers to government spying to corporate data collection. It also lets you visit websites published anonymously on the Tor network, which are inaccessible to people not using Tor. This is one of the largest and most popular sections of the darknet.