The SHOW function will display the contents of a user's (target terminal) screen on a requestor's (host) screen. The target terminal is not affected. It can be used for assistance in debugging or ‘help desk’ monitoring. The TELL function displays the contents of a master (teacher) terminal’s screen on other (students) terminal screens. The TELL function can be used to instruct terminal operators in remote locations or local classrooms on the usage of CICS applications.