These scripts are designed to manually install and update the latest stable version of Firefox on Debian, since the original repositories are usually a bit behind.

NOTE: There exists "unstable" repositories, which makes it possible to install via apt, for some versions of Debian. See this page for more info.

The first time this is used, you should begin with running first_install.sh. This will download and install Firefox, while also copying the .desktop file to /usr/share/applications/, in order to make an icon visible in the "start menu".

./first_install.sh

In the future it should then only be necessary to run the firefox_update.sh script when Firefox complains about being too old.

./firefox_update.sh

Information about this was taken from the oficcial Debian Wiki and from LinuxConfig.