X Windows is a system providing for the display and management of graphical information, in much in the same way as Microsoft's Windows Graphic Device Interface (GDI) and IBM's Presentation Manager.

The "X Org," a non-profit consortium comprising several members, developed the X Protocol in the mid-1980s to offer a graphical user interface that is transparent to the network, chiefly for the UNIX operating system. It is often said in the UNIX world that "the network is the computer," and the X protocol personifies this.

The chief difference between X and other graphical environments is the way the X Protocol has been designed as a true client-server system, meaning that it comprises two separate parts or processes that communicate in some way. Microsoft Windows and IBM's Presentation Manager merely display graphical information on the machine on which they are running, but the X Protocol breaks...