Most dark websites are not directly accessible via a normal search made through a search engine; they effectively hide themselves. They are accessible only if the addresses of those sites are known to the user. Some methods which hide websites from normal searches are:

Private Web which requires registration

Contextual Web varies as per IP

Limited access content where access is limited to certain licensed contents

Scripted content which is accessible only through links generated by JavaScript or dynamically downloaded from Web servers

Non-HTML/text content

Software where data are intentionally hidden from the regular Internet and made accessible only with special software, such as Tor, I2P, or other darknet software

Web archives which are archived versions of Web pages, including websites which have become inaccessible, and are not indexed by search engines such as Google

The industries which operate over the dark Web are known as darknet markets; this includes black market sales of illegal products, to stay hidden from governments and law enforcement agencies. The dark Web is also used in other ways, like communication between whistleblowers and protecting users from attacks or surveillance to ensure privacy in communication. But the dark Web is mostly used in black markets as it promises total anonymity.