Wayland
also: Wayland protocol, Wayland compositor
Wayland is a modern display server protocol and compositor that replaces X11, designed to be simpler, more secure, and better suited to contemporary graphics hardware and input handling.
Wayland is a communication protocol between applications and the display server (compositor) that manages what appears on your screen. Unlike X11, which has been the Linux standard for decades, Wayland eliminates unnecessary complexity by having applications send their rendered content directly to the compositor rather than communicating through a complex intermediate layer.
The protocol is event-driven and architecture-agnostic, allowing different compositors (like GNOME's Mutter or KDE's KWin) to implement Wayland support independently. Each compositor handles window management, input events, and rendering to the display.
Key advantages include better security (applications cannot spy on each other), improved performance on modern GPUs, native support for high-DPI displays, and simpler code. For example, a modern GNOME or KDE desktop running on Wayland handles touchscreen input and multi-monitor setups more intuitively than X11.
Wayland is still being refined, and some legacy applications or specialized software (like certain games or professional tools) may still require X11, which is why many distributions offer both options at login.