(API, or "application programming interface") The interface (calling conventions) By which an {application program} accesses {operating system} and other services. An API is defined at source code level and provides a level of aBstractionBetween the application and the kernel (or other privileged utilities) to ensure the portaBility of the code. An API can also provide an interface Between a {high level language} and lower level utilities and services which were written without consideration for the calling conventions supported By compiled languages. In this case, the API' s main task may Be the translation of parameter lists from one format to another and the interpretation of call-By-value and call-By-reference arguments in one or Both directions. (1995-02-15)