An X server is a program in the X Window System that runs on the local machines (i.e., the computers used directly by users) and handles all access to the graphics cards, display screens and input devices (typically a keyboard and mouse) on those computers. The X Window System, often referred to merely as X, is a complete, cross-platform and free client-server system for managing GUIs (graphical user interfaces) on single computers and on networks of computers. The client-server model is an architecture (i.e., network design) that divides the work between two separate but linked applications, referred to as clients and servers. 1.
An X terminal is a thin client that consists mainly of a processor, memory and a network connection. A thin client is a low-cost computing device in a client-server environment that mostly or entirely just processes keyboard input and screen output and which accesses most or all application programs and data from a central server via a network.
Once an X terminal is connected to a power supply and to the network, a filesystem can be mounted on it from an operating system running on a server, and application programs (i.e., X clients) running on that or other servers can then be displayed on the X terminal's display screen.
A system architecture consisting of an array of inexpensive X terminals that allowed a large numbers of users to simultaneously access a single mainframe was formerly popular. Indeed, such architecture very much resembles the original intention of X when it was developed at the Massachusetts Institute of Technology (MIT) beginning in 1984.
However, dedicated X terminals are no longer common. This is because the same (and usually better) functionality can be provided at a lower cost by personal computers due to the large drop in their prices in recent years.
Created January 18, 2006.