Deep Web vs. Dark Web: What’s The Difference?

The terms “deep web” and “dark web” are sometimes used interchangeably, but they are not the same. 

Deep web refers to anything on the internet that is not indexed by and, therefore, accessible via a search engine like Google. Deep web content includes anything behind a paywall or requires sign-in credentials. It also includes any content that its owners have blocked web crawlers from indexing.

The dark web is a subset of the deep web that is intentionally hidden, requiring a specific browser—Tor—to access. No one really knows the size of the dark web, but most estimates put it at around 5% of the total internet. Not all the dark web is used for illicit purposes despite its ominous-sounding name.

https://www.csoonline.com/article/564313/what-is-the-dark-web-how-to-access-it-and-what-youll-find.html