When you compile a program, the compiler generates an object module for the code in the program. If you use any subprograms (functions in C, subroutines in other languages) that are in an external object module, the compiler adds an external program reference to the program's object module.
The linker resolves these external references. If it finds a reference to external subprograms in an import library or in a module definition file of a DLL, the code for the external subprogram is in a DLL. To resolve an external reference to a DLL, the linker adds information to the executable file that tells the loader where to find the DLL code when the executable file is loaded.
The DLLs that you reference can be created to load when the executable that calls them is loaded (preload) or to load when they are first referenced (load on call). However, the linker does not resolve all references to DLLs by COBOL CALL statements. With the DYNAM compiler option in effect, COBOL resolves CALL identifier and CALL literal when these calls are executed.
related concepts
Static linking and dynamic linking
related tasks
Creating DLLs