“The dark web” is a phrase we’ve heard a lot in the past few years. Also known as “the darknet”, it has a reputation for being a massive place full of illicit websites.

In fact, the dark web makes up a tiny percentage of all the websites available in the world today. There are millions of sites on the World Wide Web and, it’s estimated, only 7000 to 50000 on the dark web.

So what’s the dark web?

Before we go into that, we should think about the other layers of the Internet.

The surface web

This is the web we see when we open Firefox, Chrome etc and run an Internet search. Everything is organised. Search engines like Google can and do crawl through sites on the surface web, then index them. So if you do a Google search for “bank”, you will get a list of banking brands in your location. Companies and individuals use search engine optimisation (SEO) techniques to push their sites up the lists of search results. You can look anywhere you want on the surface web and your every move is tracked.

You’d think that the surface web is the biggest part of the World Wide Web, right? Nope. It’s estimated that it only makes up about 5% of it. Here’s why…

The deep web

People often confuse “deep web” and “dark web” but they are two different things.

The deep web refers to all the sites we use but can’t reach using a search engine. For example, you access online banking via your Internet browser and can transfer money, pay bills etc. However, you can’t go to Google and search for the web page that has your bank balance on it. If your company has an Intranet site with corporate policies and staff discussion fora on it, this is part of the deep web too. Same with your medical records on the NHS Intranet.

Many of the sites we use have a home page on the surface web and then most of their other pages on the deep web. So your bank’s home page, www.mybank.com, is part of the surface web. Then all the pages you see once you’ve logged in are on the deep web.

The same goes for services like Gmail. The Gmail homepage is on the surface web and then everything behind the login page in is on the deep web.

Your every move is tracked and you’re not anonymous because your bank, e-mail provider etc needs to know who you are. It’s estimated that the deep web makes up more than 95% of the World Wide Web.

The dark web

Sites on the dark web are neither on the surface web nor the deep web. You can’t find them using search engines like Google. Indeed, you can’t even use browsers like Chrome or Firefox to surf the deep web. You need a special browser called Tor. This is available for anyone to download free of charge, but is illegal in some countries - more on that later.

Every computer on a network, including the Internet, has what’s called an IP (Internet Protocol) address. The IP addresses of sites on the dark web are hidden. This means that it’s not easy to identify and locate who’s hosting these sites and where they are hosting them.

Browsing the dark web is more private than looking around the surface web, for similar reasons. When you surf the dark web using Tor, the browser routes you through a number of computers on the Tor network, so by the time you get to the site you want, it’s hard for anyone to tell what the IP address of your device is. You don’t get perfect anonymity, but it’s much more than you get browsing the surface web using Chrome.

What’s on the dark web?

Because of the levels of anonymity afforded to website owners and people browsing the dark web, it is used for illicit and criminal activity. A study by Daniel Moore and Thomas Rid of King’s College London found that 57% of the dark web sites they classified in 2015 contained illicit material. This includes drug dealing and illegal porn. Transactions are generally financed by cryptocurrency, like Bitcoin, which makes them hard to trace.

You can buy all sorts of things on the dark web - many of which you’ve never even thought of. For this reason, you need to be very careful about what you click on. There is a high risk you could accidentally come across some very shocking items for sale. Body parts, for example.

That said, crime isn’t the preserve of the dark web: criminals can and do use the surface and deep webs to carry out their activities. Similarly, the dark web isn’t just used for illegal acts.

Many of the sites on the dark web are just like the ones you use on the surface or deep webs. I mentioned earlier that the Tor browser is illegal in some countries. This is because some governments want to stop their citizens from accessing certain websites, reading and being influenced by news from outside or they want to prevent whistleblowing.

The Tor system allows a high degree of anonymity which means people can access forbidden websites or send their information across geographical borders more safely. In fact, Facebook and The New York Times have dark web versions of their websites for people who want to use them without being tracked.

The dark web is also used for altruistic reasons. Dr Fernando Caudevilla, a Madrid-based family doctor, spends his spare time giving out free advice on harm reduction via the dark web. He knows it’s a fact of life that people take illegal drugs. Sometimes people are taking prescription medication and they don’t feel they can ask their own GP about how the drugs will react with each other. The dark web gives them a place where they can ask questions anonymously, without fear of judgement.

Can’t I just navigate to a dark web site using Chrome or Firefox if I know the URL?

In a word: no. If someone gives you the URL of a dark web site, it will most likely end in .onion as opposed to the usual .com or .co.uk. The top-level domain .onion is a nod to the fact that Tor stands for “The Onion Router”: a reference to the way users are sent through different computers on the network to reach their destination site.

If you try to visit a .onion site using a normal browser, you won’t be able to open the page.

However, you can use the Tor browser to access the surface and deep webs.

Is it illegal to go on the dark web?

It’s not illegal to browse the dark web per se, but the dark web (like the surface and deep webs) does contain illegal material. Therefore, if you decide to browse the dark web, you need to be very careful about what you look at.

Similarly, there are lots of illegal things for sale on the dark web, just like there are on the surface and deep webs, or on the streets of the town you live in. If you buy them, you’re breaking the law.

I hope this article has demystified the dark web!