It is often convenient to copy text from one window to another. For example, suppose a friend sent you a useful alias that you want to put in your .cshrc file. An easy way to do this is to use the mouse to copy the line out of the mail message and into the window where you are editing your .cshrc file. As you use the workstations more and more, you will find that you can save yourself a lot of time and effort this way.
Under the X windowing system, there are standard mechanism for copying and pasting text from one window to another. That is, the mechanism should work in any X-based application.