What Is Firefox Quantum ESR?
Firefox Extended Support Release (ESR) is an official version of Firefox developed for large organizations like universities and businesses that need to set up and maintain Firefox on a large scale. Firefox ESR does not come with the latest features but it has the latest security and stability fixes.
For end users, it's not necessary to stick with Firefox ESR. Like Mozilla's site says, it's geared towards large organizations. If your distro comes with Firefox ESR by default and it doesn't make much difference to you, then you can leave that version installed.
Firefox vs Firefox ESR on Linux - Linux Tutorials - LinuxConfig ...
What is the latest version of Mozilla Firefox ESR?
Firefox ESR 91.4. 0, See All New Features, Updates and Fixes.
Firefox ESR 91.4.0, See All New Features, Updates and Fixes - Mozilla
What's the difference between Firefox and Firefox quantum?
Firefox Is a Fast Multi-Process Browser Before the update, Firefox used to run everything in a single process. ... However, with Firefox Quantum, you can control how many processes the browser runs; by default, Quantum uses four processes to view and render web content.
What Is Firefox Quantum? - Lifewire