CICS
full spelling ： Customer Information Control System
Customer Information Control System is an IBM licensed program that was originally developed in 1969 by IBM's Palo Alto lab to provide transaction processing for IBM mainframes. CICS is runs mainly on IBM mainframe systems under z/OS. CICS is also available for other operating systems, notably OS/400, OS/2, Windows, and Linux, among others.
CICS is a transaction processing system designed for both online and batch activity. On large IBM zSeries and System z9 servers, CICS easily supports thousands of transactions per second, making it a mainstay of enterprise computing. CICS is used in bank teller applications, airline reservation systems, ATM systems etc.