X.Org Server (xorg-server) is an open source and freely distributed implementation of the X Window System (X.Org), provided by the X.Org Foundation, specially designed for the GNU/Linux operating system.
Features at a glance
Key features include input hotplug, KDrive, DTrace and EXA. It's designed to run on many UNIX-like operating systems, including most Linux distributions and BSD variants it. It is also the default X server for the Solaris operating system.
Forked from XFree86
X.Org Server is part of the X.Org software, the popular and powerful X Window System used in many POSIX operating systems, including almost all GNU/Linux distributions, as well as some BSD and Solaris flavors. The software was originally forked from the XFree86 project.
An important component of every Linux distro
This is a very important and essential component of all Linux kernel-based operating systems that run a graphical desktop environment or a window manager. Without X.Org and X.Org Server, you will only be able to use a distro from the command-line.
It’s installed by default
Of course, this means that it is installed by default in all these GNU/Linux distributions, without exception. If you remove this package from your installation, you won’t be able to access the graphical environment anymore.
X.Org, X.Org Server and X.Org Foundation
Many people get confused about these two essential components of a Linux distribution that uses a graphical session, but one should know that X.Org (X Window System) is the display server and X.Org Server is the X Window System implementation that contains several other projects, such as XCB and Xlib.
Furthermore, X.Org Foundation is the organization that governs these two projects. The X.Org (X Window System) packages are freely available for download on Softpedia.