6) Desktop environments, available repackaged on CD:
Under Windows and Mac OS you have a very limited choice as to your desktop environment (the actual interface displayed on the screen), DE for short. You get what you're given. It's a monoculture based on their file manager - Windows explorer in Micosoft Windows, and the Finder in Mac OSX.
Under Debian you get choices of several desktop environments, each with their own idea of what a good DE should be. Your choice may be influenced by which one you've used before, what your friends are familiar with, which is most similar to your current OS, or what you want to do and your PC's capabilities. You can forgo a DE altogether, if for example you want to create a server, or have an old PC so use a window manager, instead.
The look, feel and control of a Debian system can depend on many things. It can be extremely complex due to the flexibility of the system, and the users needs. Desktop environment or Window manager, and how they fit together with the huge range of applications and tool-kits, all have a bearing. Even if you choose to have no GUI, the CLI offers an amazing variety of looks and feel. The best place to start for changing the look and feel of your Debian system is the Debian repository's. Always be careful installing anything from other 3rd party external sites. If you have any doubts don't install. See: http://forums.debian.net/viewtopic.php?f=3&t=47866&
Search the repositories first with synaptic, apt or aptitude.
apt-cache search themes
apt-cache search icons
apt-cache search wallpaper
Desktop environments: (DE)
If you downloaded the first Debian CD. You will get the default Gnome Desktop which uses the GTK graphics libraries. The other most popular DE is KDE, which uses the QT libraries. There is also the XFCE (using GTK) desktop that is slightly lighter than Gnome and KDE. LXDE (GTK) is a very light DE. XFCE and LXDE are present on the same CD. Check their prospective sites before you decide which one you think is for you. You only need the first CD to get up and running. Just choose the Desktop you want. Don't download all 20 odd disks unless you need them. If your computer is powerful enough and has enough space you can install more then one DE. Then you get to choose which one you want to run at login.http://en.wikipedia.org/wiki/Comparison
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