Another way that the nomenclature is commonly used is to say that “foreground” activities occur spontaneously and at the user’s behest, while “background” activities are commonly beefier, performed on behalf of the community at large, longer-running, and therefore commonly handled by a group of batch-service processes (on the same or on different computers), who are servicing some kind of request-queue and posting their results [files ...] to some kind of results queue.   In other words, “batch jobs.”   (There’s a third category, “servers,” or “daemons,” to generally denote processes that are running all the time.)

At this point, I would suggest that you consider your overall requirement carefully, and, feel free to discuss it here.   There are, today, many good CPAN libraries which address this sort of requirement at a very high level ... POE and RPC::Any come readily to mind ... that might take you much farther, much faster, towards a robust solution for your requirement, than your initial gropings might suggest.   If you describe now what you need to do, and the environment in which you need to do it, someone [else] here will probably hand back excellent suggestions within a matter of hours or minutes, drawn directly from their personal experience.   So, I’d start there.