The IBM architecture underlying the e-mail system, defining a region or domain for electronic mail delivery.

IBM's general purpose online transaction processing OLTP software. It is an application server product, which runs under a number of both IBM and non-IBM operating systems. It integrates all the basic software services required by OLTP applications with a rich set of resources and management services in a highly available, reliable and scalable manner. CICS has been "evolving" for well over 30 years and the most current mainframe CICS is "CICS® Transaction Server for z/OS", which not only provides the more traditional OLTP services, but is also a full function Web Application Server and full function Enterprise Java Bean Server. When new technology becomes available CICS generally very quickly provides support for that technology.

See CICS.

n. An IBM licensed program that provides online transaction processing services and management for critical business applications. CICS runs on many IBM and non-IBM platforms (from the desktop to the mainframe) and is used in various types of networks that range in size from a few terminals to many thousands of terminals. The CICS application programming interface (API) enables programmers to port applications among the hardware and software platforms on which CICS is available.

An IBM application subsystem that provides file handling and data communications services for application programs.

Part of the operating system that manages resources for running applications (for example, IND$FILE). Note that TSO and CMS provide analogous functionality in other host environments.

The software used on the CSXT mainframe computer to organize massive amounts of data into manageable units called databases.