For the most part, many distros do not have graphical updaters, unless if you use a really user-friendly distribution like Linux Mint which helps takes most of the guesswork for you.
If you need to update without using the GUI, open up a command terminal and run:
[Debian and Ubuntu family] apt-get update && apt-get upgrade
[Arch family (Antergos, Manjaro, Archbang, etc)] pacman -Syu
no
The GUI uses unnecessary resources.
Yes and no. Yes, Linux has a GUI. Dozens, in fact, all running on the X Windowing System. No, Linux is not BASED on a GUI. Only Windows really has the concept of an operating system "based" on a GUI. To Linux, the X Windowing System and whatever you run on top of it is just another application.
Not sure what your question is asking, other than the GUI is displayed by the desktop manager.
No.
Yes
X Windows
gnome and kde
The Linux kernel itself does not include a GUI. However, most Linux distributions have one. Yes, Linux have a GUI.Today many kind of vendor available in Linux Like Redhat fedora,Ubuntu,Suse, Mandriva and many more. Those Linux version provide Cmd and GUI mode for work.
x windows
There are many differences between the Graphical User Interfaces of Windows and Linux. There are similarities as well. To be exact, Linux, itself has no GUI per se. The GUI(s) that you can use, and there are literally hundreds to choose from, are separate programs running under Linux. [speaking simply here]Linux itself is the core (kernel) of the Operating System, whereas the GUI, the file managers, web browsers, chat programs etc, are all applications that give the OS "features". With Windows you only have the included GUI, that is unless you install a modification such as WindowBlinds(TM). Linux, and many other POSIX compliant OS's can use many GUI, here is a brief listing and some links to GUI sites. KDE - The K Desktop Environment: http://kde.org/Gnome (Pronounced with a hard "Guh" as in Guh-Nome: http://gnome.org/Enlightenment: http://www.enlightenment.org/blackbox: http://sourceforge.net/projects/blackboxwmAfterStep: http://freshmeat.net/projects/afterstep/ and many more...
Many Linux users find the command line quicker than using the Graphic User Interface (GUI).