It took me a while to understand the X Window System’s definitions of client and server. An X client refers to an application that uses the X11 protocol, such

It took me a while to understand the X Window System’s definitions of client and server. An X client refers to an application that uses the X11 protocol, such as Firefox or GIMP. An X server implements the X protocol and connects to a display. On many computers, both the client and the server run on the same machine. However, if I’m launching an instance of Firefox that is running on a remote machine, then the X client is running remotely while it is using my local X server. Some people get confused, however, since usually we think of servers as remote machines. I have no issue with the terminology, but different naming could ease confusion.