When the cpu isn't doing anything, it runs the idle process. I heard that this process looks for programs that are waiting in the queue so that the cpu can run them. Is that all it does? I am also interested in knowing the file name of the system idle process in the various OSes.
Yes. All multitasking OSes have one. The process does nothing at all. It just is a placeholder when nothing else is running. Having a do-nothing process is simpler than having a special case when the processor is idle. It is always the lowest priority, so is always replaced by something that can do real work.
It doesn't do this. The OS scheduler does this. The scheduler is part of the kernel (almost always) and is not a process.