It's a command to start the X server for running Linux in graphical mode, if you have any of the desktop environments and/or window managers installed.
Different Linux distributions can use different GUI's some will use Gnome or KDE. Most distributions will let you choose which you want. If you have an older machine you might want to use XFCE or LXDE window managers. If you are looking for a distribution you might want to try Linux Mint it uses all of these Window Managers.
Ubuntu( linux Operating System)
There is no singular user interface for Linux. Linux itself makes no requirement for a user interface. There are plenty of interfaces: GNOME, KDE, Xfce, LXDE, BASH, ZSH, CSH, TSH, FISH, and dozens of window managers.
ALT+F4. A lot of window managers and desktop environments on Linux also use this shortcut.
Unlike Microsoft Windows, the Linux system is extremely configurable. The X-Windows system itself just puts the windows on the display device and takes input from devices (keyboard and mouse). It has been written to be network aware from the start so that programs running on one machine can have their display and input on another machine. (When running X-windows on a single machine it uses the loop-back network of the machine.) However, it requires a windows manager to add the buttons, window borders and to handle clicks to resize the window, etc. There are various window managers available, from the basic twm to powerful ones like Enlightenment; the different window managers offer different things. There are also two projects which give Linux the desktop of Microsoft Windows: Gnome and KDE. These both still require a window manager. It is the configuration of the window manager that makes the Linux desktop look like it does, so that it can look like Microsoft Windows (if required).
There is no set file manager in linux. Examples of Linux file managers include but: Nautilus (GNOME) Thunar (XFCE) Dolphin (KDE)
yes there is mac and there is Linux
I don't.
Yes. Compiz Fusion allows for 3D window management.
use Linux
unix