The following is an excerpt from my post: How Linux GUIs Work: An Introduction to X11, Display Managers, and Desktop Environments. This has been separated into its own post for easier reading.
The desktop environment is the most (easily) visible component of the GUI. It handles the taskbar, menus, maximizing and minimizing applications, stacking applications (things on top of each other), desktop icons & wallpaper, launching most programs, WiFi connections, volumes, clipboards and such. It handles visual aspects as well, including icons, system colors and themes used in applications and other GTK/QT settings.
A lot of essential parts of the system ship with a desktop environment. Every (full) desktop environment ships with its own suite of applications for file browsing, settings, web browsing. As such, the same computer can look and behave vastly different among various computers. This is also due to desktop environments being based on either the GTK+ or QT toolkits.
For example, some common desktop environments with specs:
|Desktop Environment||Toolkit||File browser|
Desktop environments connect with a lot of other system services to perform functions, in a way that is easy for the user to interact with. For example, the volume sliders on most DE’s actually just send commands to PulseAudio, the network manager is usually handled by NetworkManager, and so on.
Essentially, most of what you interact with (outside of applications) is dependent on the DE you choose. Everything from settings, to file managers, to lockscreens, to menus, to icons are determined by the DE. SO MUCH of the look, feel, and functionality can change based on the DE. There is so much to cover that I will probably end up creating another post just on this.
Now even DE’s have a core, which actually handles the applications. There are 2 main types: stacking and tiling. Stacking is what most users are used to. Its used on Windows, MacOS and most environments. Its when open applications ‘stack’ on top of each other. If I open Firefox, then Thunderbird, Thunderbird will appear ‘on top’ of Firefox, and the keyboard will interact w/Thunderbird. If you click on Firefox, the focus switches, and FF becomes ‘on top’. Meanwhile, in tiling desktops (like i3), opening 2 apps opens them side by site, usually following a tree layout.
Common desktop environments include:
- i3 (tiling)