What is x11 forwarding?

X11 forwarding is a method that allows users to run graphical applications on a remote server while displaying the interface on their local machine. It utilizes the X Window System (X11) protocol, which enables the transmission of graphical data over a network. When a user connects to a remote server via SSH with X11 forwarding enabled, any graphical applications launched on the server will appear on the user's local desktop. This feature is particularly useful for accessing applications that require a graphical user interface without needing to be physically present at the server.