X11 has been the Linux graphical display protocol since the 1980s; Wayland is its modern successor, and the ongoing transition between them is one of the longer-running architectural shifts in Linux desktop history.
X11’s Design and Its Age
X11 was designed in an era of networked, shared computing — its network-transparent architecture (a program’s display could genuinely run on a different physical machine than where it was rendered) was innovative for 1984, but that same design carries real security and performance costs on a modern single-user desktop that never needed that transparency in the first place.
Wayland’s Core Change
X11: apps draw through a central X server, which then composites everything
Wayland: each app renders its own buffer directly; the compositor
just displays those buffers - fewer indirection layers,
and each window is properly isolated from others by default
Why Isolation Matters
Under X11, any application can technically read another application’s window content or inject fake keystrokes into it — a genuine, longstanding security weakness. Wayland isolates each application’s rendering by design, which is a meaningful security improvement, but it’s also exactly why some older X11-specific tools (certain screen recorders, remote desktop tools, accessibility software) needed significant rework or compatibility layers (XWayland) to keep functioning.
Where Things Stand
Most major distros now default to Wayland, with XWayland providing compatibility for applications not yet natively ported — X11 remains available and actively used specifically where an application or workflow genuinely still depends on its network transparency or lacks a Wayland-native equivalent.