The function of a desktop environment in a GUI system is to provide a user-friendly interface for users to interact with their computers. It encompasses the visual layout, icons, windows, and menus that users interact with. Desktop environments enable multitasking and organization of workflows by allowing users to easily navigate applications and files. Popular examples include GNOME and KDE for Linux, as well as Windows and macOS. A well-designed desktop environment contributes significantly to overall user experience.