The World Wide Web is made up of three main layers: the surface web, the deep web and the dark web.

When you search the web, read news from a webpage or shop for sneakers online, you’re most likely on the surface web. Most people are here when they’re online. 

If you sign in to your email account, you head into the deep web. This part of the web stores information protected by passwords. Your email, bank account and online health records are all on the deep web. 

The deep web also contains the dark web. And unlike the other layers of the web, the dark web can’t be seen from normal web browsers. Users are anonymous, and their activity isn’t tracked. 

Websites on the dark web end in “.onion” rather than in endings like “.com” or “.gov.” Users need a special browser to access sites on the dark web. One example is The Onion Router, or Tor for short. And just as an onion has many layers, Tor has many levels of encryption. This is what helps keep users anonymous.

U.S. military researchers created dark web technology to send and receive messages anonymously. While its name may sound threatening, the dark web is used by some legitimate businesses and organizations. 

Some journalists use the dark web to protect the identity of sources. News organizations also use it to make journalism accessible in places where it’s blocked. Still, because users are anonymous, the dark web is also used by criminals for illegal activities like selling stolen information.