Where does x-windows fit in the client-server model? Does it come in the client side or the server side?
When a user connects to a remote m/c from his desktop and runs a GUI application (like xclock), from where are the window borders and menu drawn? The x-windows should be installed in the remote m/c or the desktop m/c for the menus and border to be displayed?

This sounds suspiciously like a homework assignment. You'll learn a lot more by doing your own homework. People interviewing candidates for jobs can quickly determine who just learned some terms from those who actually know what they're doing.

Your suspicion is wrong then :-). I am not a student.. Just started using linux and curious to know how certain basic things are working in Linux. People coming from windows world find even trivial things in linux bit confusing..

My apologies then.

From the standpoint of "client/server" the machine that you launch the X application on (e.g. when you type "xclock") is the "server" for that application and the machine where the application actually get's displayed is the "client". Note that you can both launch an application and display it on the same machine (e.g. when you are in the GUI Console of a Linux box - all the items you see are X-Windows).

The X display implementations contain information such as fonts and other things that the application directs to be used. The application itself is still running on the machine that launched it. This means you're using more resources on the host that launched the application than on the one that displays it. Due to this model you're host doesn't have to know anything about the application you launched. It simply knows generic information common to all X windows. All the detail of the X window is provided by the launching application.

You can run X-Windows on top of MS-Windows by using tools such as Exceed ($$$) or Cygwin/X server (FOSS). You can also open VNC session from Windows to Linux/UNIX and run X inside the VNC session.

Lots of good info:

http://en.wikipedia.org/wiki/X_Window_System
http://en.wikipedia.org/wiki/X_Windo..._core_protocol

Thanks for the reply. Actually, my question is not about working of x-client/server. i am already aware of how the x-client/server works. I was curious to know about the redirection to x-windows manager. whenever a request comes to x-server from a client to display something, the request is redirected through x-windows manager. Where and how does this redirection occur?
For instance, when xclock is invoked, the application sends request to x-server to show the clock's face. Before the face of the clock is displayed, the request is redirected to x-windows manager which draws window border and title bar. Is this redirection done by x-client or x-server? If there is just a bare x-client/server without any windows manger installed, will the clock's face be displayed without any windows border?