A command-line symbol used for piping that is supported by all versions of Microsoft Windows. Piping allows you to make the output of one Windows command the input for another command. The | symbol is generally referred to as the pipe symbol.
Normally, Windows sends the output of a command to the screen. For example, suppose you open a command prompt on a machine running Windows 2000 Server and you type the command
tree c:\
The screen will display the entire directory tree of your C drive, starting with the root. Because there is more than one screen of information, the screen will scroll. To view the information more conveniently, pipe the output of the above command into the more command. The more command is a filter command that displays one screen of information at a time, waiting for you to press any key to view the next screen. You would thus type the following command
tree c:\ | more