http://wq64njzhhlpj42v5b6sm2uf42qf7fuhqhvji3aacyt244so7iw2dlzid.onion/tor-browser.php
This refers to the browser's layered approach to privacy, like the layers of an onion. The Tor Browser directs internet traffic through a worldwide network of servers, with each relay server adding an additional layer of encryption, thereby increasing the privacy and anonymity of the user.