The X Server is also known as:
and is an important part of the X Windows System.
It's located on your machine (laptop, localhost).
All graphical UNIX/LINUX applications connect to an X-Windows Server to display graphical data on the monitor of the computer when you use the X Windows system.
The X-Windows Server is a program that acts as an interface between graphical UNIX/LINUX applications and the graphics subsystem of the computer.
Microsoft Windows does not come with support for X, but many third-party implementations (X-Windows server) exist such as: