Definition - What does X Terminal mean?
An X terminal is an input terminal with a display, keyboard, mouse and touch pad that uses X server software to render images. Used as an open-source windowing system known as the X Window System, the X terminal does not perform application processing - this is handled by the network server.
X allows applications to run on a network server but be displayed on the X terminal or desktop machine. During the 1980s-1990s, this industry stride was significant because servers were much more powerful than personal computers. X and the X terminal were therefore the forerunners of modern thin clients (network computers) and network server operating systems.
An X terminal is also known as a diskless computer.
Techopedia explains X Terminal
In X, the terms client and server are used from the software’s perspective. Thus, the X server supplies a screen, keyboard, mouse and touch pad to client applications. The X terminal uses a Unix-based operating system residing on a mainframe, minicomputer or workstation.
X was developed at the Massachusetts Institute of Technology (MIT) in the 1980s. In 1987, version X11 was introduced, followed by many revisions.
X uses client/server architecture, which means that X clients applications usually run inside servers but also are able to run inside client machines. X clients and the X server communicate via the X Protocol.