X Window System

The X Window System, often referred to as X11 or simply X, is a windowing system for bitmap displays common on UNIX-like operating systems. It provides the basic framework for building graphical user interfaces (GUIs), including drawing and moving windows on the screen and interacting with a mouse and keyboard. X is network-transparent, allowing applications to run on one machine while displaying on another, facilitating remote graphical sessions and flexible computing environments.