X Concepts

What is a display server?

A display server is a program whose primary task is to coordinate the input and output of its clients to and from the rest of the operating system.

Every display server has its own protocol for communication purposes. The word display-server can be more commonly referred on Linux.

Since Windows does not really have an independent display server, instead it is built into

the operating system itself(kernel).

As you may be aware of, on Linux the kernel tends to be more modular, and thus the display server is a separate program.

It is really important to note the difference between a display server and its C library.

Display Server	C library
X	Xlib
Wayland	GTK/QT

Xlib is a library that allows you to communicate with the X display server(aka X).

X is a display server which runs on the port 6000.

Nowadays, it is more common to use wayland instead of X, but X is still used by many applications.