Meaning – The term load module, refers to all or part of a computer program in a form suitable for loading into main storage for execution. A load module is usually the output of a linkage editor.
Creating a load module that can be stored in a program library requires that you use the binder or linkage editor. In all cases, the load module is relocatable, which means that it can be located at any address in virtual storage within the confines of the residency mode (RMODE).
Once a program is loaded, control is passed to it, with a value in the base register. This gives the program its starting address, where it was loaded, so that all addresses can be resolved as the sum of the base plus the offset.
Example of usage – “Relocatable programs allow an identical copy of a program to be loaded in many different address spaces, each being loaded at a different starting address.”