Google only indexes a tiny fraction of the internet. By some estimates, the web contains 500 times more content than what Google returns in search results. The links that Google and other search engines return when you type in a query is known as the “surface web,” while all the other, non-searchable content is referred to as the “deep web” or “invisible web”.
The dark net, or dark web, constitutes a small fraction of the deep web. The dark web is made up of purposefully hidden websites and services. Both the owners and users of the dark web are anonymous. Although not everything on the dark net is illegal, it’s where you’ll find many of the internet’s black markets, hacker forums, malware vendors, and other illicit activity.
How to access the Dark Web safely: Step-by-Step Guide for 2021 (comparitech.com)