Darknet is the deepest part of the so-called Deep Web sector of the Internet, the content in which is not indexed by search engines. And this is done intentionally. If the rest of the network is striving to increase the rating of the site and its attendance, then in this case they are trying to make it as invisible as possible to the general public, and first of all, to law enforcement agencies. For these purposes, special software, encryption, non-standard protocols and domain names are used.
For the same reason, accidental penetration into the Deep Web is impossible – at least you need to install a special application for this.
The second line of protection is an information search system different from the usual Internet. There are no search engines familiar to modern users, in which it is enough to ask a question to get a list of resources corresponding to it. You will have to search for a suitable site in the link directories (Hidden Wiki, TorDir and TorLinks) manually, but you cannot completely rely on them either, since resources in the Darknet tend to change addresses often, or even disappear altogether. By the way, this also applies to the link directories themselves.