(TeleProcessing monitor or Transaction Processing monitor) A control program that manages the transfer of data between multiple local and remote terminals and the application programs that serve them. It may also include programs that format the terminal screens and validate the data entered.

In a distributed client/server environment, a TP monitor provides integrity by ensuring that transactions do not get lost or damaged. It may be placed in a separate machine and used to balance the load between clients and various application servers and database servers. It is also used to create a high availability system by switching a failed transaction to another machine. A TP monitor guarantees that all databases are updated from a single transaction (see two-phase commit).

Examples of popular TP monitors are CICS, a veteran TP monitor used on IBM mainframes and the Unix-based Tuxedo and Encina products. See BEA Tuxedo and Encina.