What is RMI?

The Java Remote Method Invocation API, or Java RMI, is a Java application programming interface for performing remote procedure calls. There are two common implementations of the interface, the initial one to be implemented known as JRMP and a version compatible with CORBA. Usage of the term RMI may denote solely the programming interface or may signify both the API and JRMP, whereas the term RMI-IIOP, read RMI over IIOP, denotes the RMI interface delegating the most of the fuctionality to the supporting CORBA implementation.

The original RMI API was generalized somewhat to support different implementations. Additionally, work was done to CORBA, adding a pass by value capability, to support the RMI interface. Still, the RMI-IIOP and JRMP implementations are not fully indentical in the provided possibilities.

About this Terminology
This terminology is from The Wikipedia which is published under the GNU Free Documentation License.