I would like to learn more about "What" Firefox stands for?

hello hildOrum, a good starting point would be mozilla.org/mission.

Firefox is the third name of the browser we know as Firefox. It was Phoenix for 0.1 to 0.5 then Firebird for 0.6, 0.6.1, 0.7 and then it changed to the current Firefox as of 0.8

Phoenix was in use by Phoenix technologies and Firebird was already in use shortly before by firebirdsql.org

Otherwise you question of what Firefox stands for is a bit vague.

And yes folks, Firefox did not start at version 1.0 in November 2004 as some sites and people wrongly claim.