A GUI is composed of several components that work together to display and manage the graphical elements on the screen. At its core, the OS kernel handles low-level tasks such as memory management, process scheduling, and device drivers. Device drivers are necessary to communicate with hardware devices, such as keyboards, mice, monitors, and graphics cards. The windowing system is a software layer that provides basic functionality for creating, moving, resizing, and drawing windows on the screen. It also handles input and output events from devices and applications. The window manager controls the appearance and behavior of windows, such as title bars, borders, buttons, and menus. It also implements policies for managing windows like focus, stacking, and tiling. The widget toolkit is a library of graphical elements that can be used to create user interfaces for applications. It provides common widgets such as buttons, text fields, sliders, and menus as well as logic for handling user interactions with them. Finally, a desktop environment is a collection of applications and utilities that provide a consistent user experience for the OS. It includes features like desktop wallpaper, icons, taskbar, file manager, system settings, and applications launcher.