Very true - the X-windows graphical interface was not available in Unix systems for a long time after Unix was available.
Very true - the X-windows graphical interface was not available in Unix systems for a long time after Unix was available.
Several different versions of UNIX have GUI's or Graphical User Interfaces. The most common example of UNIX with an interface is Mac OS X.
If you mean what OS it is OSx Mountain Lion. OSx is a Unix bases graphical interface.
It in UNIX the GUI is separate from the operating system itself. You can uninstall the GUI and still have a completely working UNIX system.
If you are asking about the graphical interface, windows XP comes with just 1 interface, and it can be customized to a point, but that is somewhat limited. Unix comes with multiple graphical desktop managers, not just one. Users can pick and choose which environment is best for them. With Windows, the choice is already made for the user. Handling of icons and desktops are very different in Unix and Windows. The list would be too long to detail in this answer.
Yes, Unix has several variants of Graphical User Interfaces that may be used instead of the command line if the user wishes it.
A shell is a command interpreter. This is not limited to Unix. The programs COMMAND.COM or CMD.EXE are also shells in the DOS/Windows environments. The program EXPLORER.EXE is also a shell, though with a graphical interface.
If you are referring to the desktop as being a graphical user interface then Unix is capable of running without it. A GUI was a more recent addition to Unix, meaning that the earlier versions just used a command line and had no desktop environment at all. Today, you can install versions of Unix or Linux that do not have a graphical component at all, and several administrators (such as myself) prefer not to use a desktop.
Unix is an operating system that provides a Common User Interface (CUI) for controlling a computer. Thus CUI can run an application that provides a Graphical User Interface (GUI) which makes controlling what the computer does a little easier (e.g. GNOME - The GNU Object Model Environment).
Unix and Unix-like systems would be referred to as command interpreters because of the nature of their interface. These systems are interacted with via a shell (i.e. Bash), which is a 'command-line interface' where the user types in text commands and they are executed by the system. This is in contrast with modern operating systems where the primary method of interaction is via a 'graphical user interface' or GUI, where the system is represented with graphics (like windows, cursors, toolbars etc.). These modern OS's still include command-line interfaces, like Command Prompt in Windows and the Terminal in OSX.
You can log in via telnet or ssh protocol for a command line prompt environment to Unix, or you can use a graphical user interface such as KDE or Gnome, or the CDE environment via X-windows. In any of these protocols, you must supply a username and password to successfully log into the Unix system.
Many Unix and Linux servers come without a graphical user interface, and the text mode interface is the default. For those systems using a GUI, there is a 'terminal' tool that you can select from the menu to allow text interactions.