Quote:Tor Browser is a web browser specifically designed for privacy and anonymity. The web browser is a modified version of Firefox ESR that includes privacy tweaks and even some extensions to improve privacy and security on the Internet.

What makes it special is that all connections go through several severs of the Tor network before they connect to the destination.

Connections to Tor improve privacy when you are online but could you, in theory, run Tor Browser without Tor?
Tor Browser without Tor would still provide better out-of-the-box privacy than Firefox ESR or Firefox Stable -- and other browsers. It is arguably the browser with the best default privacy configuration which might make it attractive to some users.

Dropping Tor reduces privacy while online but that can be compensated, e.g. by connecting to a VPN or even chaining VPN services and it would speed things up significantly. Tor is the better choice when it comes to critical tasks, e.g. leaking documents or communication.

Full reading: https://www.ghacks.net/2018/11/26/can-you-use-the-tor-browser-without-tor-connection/