A tar.gz (or tar.bz2, or tar.xz) file, commonly called a "tarball", is just a compressed file or set of files. It can contain anything, including just source code, or precompiled programs such as you found in Mozilla's. Mozilla also distributes their source code in a tarball, it's just harder to find.
Currently, the Firefox, Thunderbird, and Seamonkey in the repositories are just the Mozilla versions put into a "deb" package, plus some extra goodies so they show up in the menu. FF 29.0.1 is currently in the test repo, 28.0 in the main community repo. Debian changes Firefox a bit with some patches, so has to legally change the name to Iceweasel per the Mozilla license. Currently in the standard repos, you can get a long-term support release 24.5, but there's also the mozilla.debian.net repository which should have the newest release.
Also, those compiling directions are only the very simplest case. It's as if I wrote:
How to become an NBA champion:
1. Get four other people.
2. Bounce the ball with one hand, throw it to other people on your team.
3. Put the ball through your goal more than the other team does for their goal.
4. Profit!
Can we say "all major software are pushed to the online repository servers and therefore Synaptic can contact the repositories and download them" ?
That's what we'd have in an ideal world, but some software still has to be installed from outside the repos, maybe due to a license issue, or maybe a problem with compiling the latest version on a stable base. For example, we have an older version of Calibre, the great ebook program, in the repositories, but you can get and install, or update the latest version with a long, magical command off their webpage:
Code: Select all
su
<password>
wget -nv -O- https://raw.githubusercontent.com/kovidgoyal/calibre/master/setup/linux-installer.py | sudo python -c "import sys; main=lambda:sys.stderr.write('Download failed\n'); exec(sys.stdin.read()); main()"