There are several different internet sites on the dark web that allow criminals to purchase anything from drugs to hitman. To access these sites, you must enter the realm of the dark web. To do so, using a tor browser along with a VPN will completely conceal the identity of the computer that is accessing the dark web. These are the two primary tools that criminals and you should use if you are trying to remain anonymous on the internet.
The first tool is called IP Vanish, which is a VPN (Virtual Private Network). A Virtual Private Network is used to create a secure encrypted connection over a public network. This can then be used to surf the web from a location that the computer is not located at. In other words, this masks the location of the computer while retaining a secure encrypted connection to the network to keep you 100% anonymous.
The second tool that is important to utilize and understand is called a TOR browser. A TOR browser is used to reroute the IP address through multiple different machines making it harder to trace the location of the host machine. This provided with each request to the server creates a different path to the request each time. If the first time the computers routed through 1,2,3,4 the second request may route through 3,2,1,4. This keeps it random and makes it harder to figure out which system is sending the request. If this is used along with the VPN above, it will appear that the random IP addresses are even in another country along with the suspected host machine.
These are the two primary tools used in regards to keeping an online identity anonymous when surfing the web. If IP vanish and TOR are used in conjunction with each other, there is a much higher chance of success. The ultimate goal when using tools like this is to provide complete anonymity to the user of the host computer, making it a secure web experience.