A pipe is a named or unnamed buffer used to pass data between processes. A process writes to or reads from a pipe as if the pipe were standard input or standard output. A parent process can use pipes to control the input that a child process receives and to receive the output that the child process produces. There are two types of pipes - named and unnamed. The only supported pipe to be used between a DOS application in a VDM and an OS/2 program is the named pipe.