what are the advantages of using the firefox browser? since I see that the distributions always come pre-installed with firefox?

Firefox is FOSS for the most part, very secure, well-developed and well-maintained, isn't tied into the Microsoft or Google ecosystems, has good privacy protections and user-features (containers and so on), and has been a Linux standard for years. I don't use Firefox, but it is a solid choice and that is the most likely reason almost all distros pre-install it.

    Kevinsotovalle The answer is in the history of browsers. At the time Chrome was introduced in 2008, Internet Explorer was in trouble for a lot of reasons, Firefox was in the doldrums despite relatively high market share, and Chrome was a breath of fresh air for users -- simple, elegant and fast. Chrome caught on, increased market share through word of mouth and a heavy advertising campaign by Google, and is now a habit for most people. "Google it" has become a household phrase in the way the "Xerox it" was thirty years ago.

      Firefox has its own engine. All others popular browsers rely on Blink/Webkit.

      So if you don't want a monopoly of Apple & Google on the web standards use Firefox.