The term "dark web" refers to a part of the internet that is not indexed by standard search engines and requires special software, like Tor, to access. It comprises websites that emphasize user anonymity and privacy, often used for various purposes, including political activism, whistleblowing, or illegal activities such as illicit drug sales. The dark web is distinguished from the deep web, which contains unindexed content like private databases and password-protected sites, highlighting the need for careful navigation due to associated risks.