CICS® is often used as a single system with associated data resources and a network of terminals. However, CICS can also be used in a multiple-system environment, in which it can communicate with other systems that have similar communication facilities. This sort of communication is called CICS intercommunication.
CICS intercommunication is communication between a local CICS system and a remote system, which might or might not be another CICS system.
For information about accessing CICS programs and transactions from the Internet, see Internet, TCP/IP, and HTTP concepts. For information about accessing CICS programs and transactions from other non-CICS environments, see Overview of CICS external interfaces.