Definition
Interface Definition Language ( Distributed System)
An interface definition language (IDL) is a declarative language for specifying a service interface in a distributed system, independently of its implementation. Its declarations describe exposed operations, their input and output parameters, and the data types used.
This gives clients and servers a shared interface specification, even when implemented in different programming languages. An IDL generally specifies the interface’s structure, not its complete behavioural semantics; the meaning of operations and their required behaviour often need accompanying documentation.