(1) A program service provided through a programming interface. See also action service.
(2) A set of documented interfaces between the z/OS operating system and higher level applications that want to access functions specified in the Single UNIX Specification and earlier standards.
(3) Services that are provided by IMS for use by IMS exit routines. These services provide clearly defined interfaces that allow exit routines to request various functions, such as acquiring storage or finding an IMS control block.