What you need to know about CICS

CICS® is a transaction processing subsystem that provides services for a user to run applications by request. It enables many users to submit requests to run the same applications, using the same files and programs, at the same time. CICS manages the sharing of resources, integrity of data, and prioritization of execution, while maintaining fast response times.

A CICS application is a collection of related programs that together perform a business operation, such as processing a product order or preparing a company payroll. CICS applications run under CICS control, using CICS services and interfaces to access programs and files.

You run CICS applications by submitting a transaction request. The term transaction has a special meaning in CICS; See CICS transactions for an explanation of the difference between the CICS usage and the more common industry usage. Execution of the transaction consists of running one or more application programs that implement the required function.

To develop Java applications for CICS, you have to understand the relationship between CICS programs, transactions, and tasks. These terms are used throughout CICS documentation and appear in many programming commands. You also have to understand how CICS handles Java applications in the runtime environment.